Online earners face a unique financial vocabulary. The IRS sends 1099-Ks. Payment processors talk about interchange fees and chargeback ratios. Accountants ask whether you use cash or accrual basis. Your retirement depends on understanding the difference between a Solo 401(k) and a SEP IRA. This glossary defines all 80 terms in clear, plain English—organised by category so you can find exactly what you need or read straight through to build your financial literacy from the ground up.
80
Terms defined across 7 categories
15.3%
Self-employment tax rate on net earnings
$69K
Max Solo 401(k) contribution in 2026
Glossary Categories
- Foundational Tax Terms (16 terms)
- Business Structure & Legal Terms (10 terms)
- Income & Documentation Terms (8 terms)
- Banking Terms (10 terms)
- Payment Processing Terms (10 terms)
- Retirement Account Terms (10 terms)
- Investment Terms (8 terms)
- Business Finance & Metrics Terms (9 terms)
- Frequently Asked Questions
RELATED: THE COMPLETE REFERENCE
Complete Finance and Money Guide for Online Earners 2026
Every strategy, every system, every tool—the most comprehensive resource on EarnifyHub. Use this glossary alongside it.
Foundational Tax Terms (16 Terms)
Why this matters: These are the terms that appear on every tax form, IRS notice, and accountant conversation. Understanding them is the difference between informed decisions and costly guesswork. See also our complete guide to tax deductions for online businesses and the quarterly estimated tax payments guide.
Gross Income
The total amount of money you receive from all sources before any deductions, expenses, or taxes are subtracted. For online earners, this includes every payment from clients, platforms, affiliate networks, ad revenue, and product sales—regardless of whether you received a 1099 form for it. The IRS requires you to report all gross income, not just what appears on 1099s.
Adjusted Gross Income (AGI)
Your gross income minus specific "above-the-line" deductions such as self-employed health insurance premiums, retirement contributions (SEP IRA, Solo 401k), and half of your self-employment tax. AGI is a critical number because it determines eligibility for many tax credits, deductions, and IRA contribution limits. Reducing your AGI is one of the most powerful tax strategies available to online earners.
📖 Deep dive: Tax Strategy for High-Income Online Earners
Taxable Income
The portion of your income that is actually subject to tax after subtracting all deductions (standard or itemized) and any qualified business income deduction from your AGI. Not all income is taxable—deductions like the home office deduction, equipment write-offs, and retirement contributions reduce taxable income without reducing your actual cash flow.
📖 Related: Home Office Deduction Guide 2026
Marginal Tax Rate
The tax rate applied to your next dollar of income—the highest bracket your income reaches. In 2026, federal marginal rates range from 10% to 37%. This is the rate you should use when evaluating whether a deduction (which reduces your top-bracket income) is worth pursuing. It is not the rate applied to your entire income.
Effective Tax Rate
The actual percentage of your total income that you pay in taxes—calculated by dividing total tax paid by total income. Because of the progressive tax system, your effective rate is always lower than your marginal rate. This is the number that reflects your real tax burden.
Schedule C (Form 1040)
The IRS form used by sole proprietors and single-member LLCs to report business income and expenses. This is the single most important tax form for most online earners. On Schedule C, you list your gross receipts and subtract all ordinary and necessary business expenses to arrive at your net profit (or loss)—which then flows to your Form 1040 and is subject to both income tax and self-employment tax.
📖 Related: IRS Audit Triggers for Online Businesses
Form 1040
The standard IRS form that all US taxpayers use to file their annual individual income tax return. Your Schedule C net profit, along with W-2 income, investment income, and other sources, all flow onto Form 1040. The form calculates your total tax liability, applies credits and payments (including quarterly estimated payments), and determines whether you owe additional tax or receive a refund.
Self-Employment Tax (SE Tax)
The 15.3% tax on net self-employment income that covers Social Security (12.4%) and Medicare (2.9%) contributions—the equivalent of what an employer and employee together pay for a W-2 worker. This tax applies from the first dollar of net profit (above $400). Half of the SE tax is deductible as an above-the-line adjustment to income. Read our full guide: Self-Employment Tax Reduction Strategies 2026.
Quarterly Estimated Tax
Tax payments made four times per year (April 15, June 15, September 15, January 15) by self-employed individuals who do not have taxes withheld from their income. Failing to pay sufficient estimated taxes triggers an underpayment penalty. The safe harbor rule allows you to avoid penalties by paying at least 100% of last year's tax liability (110% if your AGI exceeds $150,000) in equal installments.
📖 Full walkthrough: Quarterly Estimated Tax Payments 2026
Tax Deduction
An expense that reduces your taxable income—not a dollar-for-dollar reduction of your tax bill. A $1,000 deduction for someone in the 24% bracket saves $240 in taxes. Common deductions for online earners include the home office deduction, equipment and software expenses, internet and phone costs, advertising, professional development, and contractor payments.
📖 Don't miss these: Tax Deductions for Online Businesses 2026
Tax Credit
A dollar-for-dollar reduction of your actual tax bill—far more valuable than a deduction. If you owe $5,000 in taxes and claim a $1,000 tax credit, your bill drops to $4,000. Credits exist for health insurance premiums (Premium Tax Credit), retirement savings (Saver's Credit), and certain business activities. Unlike deductions, credits reduce tax liability directly regardless of your marginal rate.
Standard Deduction
A fixed dollar amount that reduces the income on which you are taxed, available to all taxpayers regardless of actual expenses. For 2026, the standard deduction is approximately $15,000 for single filers and $30,000 for married filing jointly (adjusted for inflation). You choose between the standard deduction and itemizing—whichever is larger. Business expenses on Schedule C are separate from and in addition to the standard deduction.
Itemized Deduction
Specific expenses you can deduct instead of taking the standard deduction—including mortgage interest, state and local taxes (capped at $10,000), charitable contributions, and medical expenses exceeding 7.5% of AGI. Most online earners take the standard deduction because their itemized deductions don't exceed the threshold, but high-income earners with significant mortgage interest or charitable giving should compare both.
Tax Bracket
A range of income taxed at a specific rate within the progressive tax system. For 2026, the seven federal brackets are 10%, 12%, 22%, 24%, 32%, 35%, and 37%. Only the income within each bracket is taxed at that bracket's rate—moving into a higher bracket never reduces your after-tax income on the dollars earned below it.
Withholding
Taxes taken directly from your paycheck by an employer and sent to the IRS on your behalf. Since online earners typically don't have an employer, they must replicate withholding themselves by setting aside 25–30% of every payment and making quarterly estimated tax payments. The W-4 form determines how much your employer withholds if you have both a job and a side business.
Qualified Business Income Deduction (QBI / Section 199A)
A deduction that allows eligible self-employed individuals and small business owners to deduct up to 20% of their qualified business income from their taxable income. The deduction phases out for higher-income earners in certain service businesses. This is one of the most valuable deductions available to online earners but has complex limitations based on income, business type, and W-2 wages paid.
📖 Learn more: Tax Strategy for High-Income Online Earners
Business Structure & Legal Terms (10 Terms)
Why this matters: Your business structure determines your tax obligations, personal liability, and the paperwork required to stay compliant. Choosing incorrectly can cost thousands. See our full comparison: LLC vs Sole Proprietor vs S-Corp 2026.
Sole Proprietorship
The default business structure for anyone earning income independently without forming a separate legal entity. No formation paperwork is required—you simply report income and expenses on Schedule C of your personal tax return. The downside: there is no legal separation between you and the business, meaning personal assets are at risk if the business is sued. Also called a "sole prop."
LLC (Limited Liability Company)
A legal entity formed at the state level that creates a separation between personal and business assets—protecting personal assets from most business liabilities. A single-member LLC is taxed exactly like a sole proprietorship by default (pass-through taxation on Schedule C) but offers liability protection. LLCs can elect to be taxed as an S-Corp once income justifies it. Formation costs range from $50–$800 depending on the state.
S-Corporation (S-Corp)
A tax election—not a legal structure—that an LLC or corporation can make to change how it's taxed. Under S-Corp taxation, the owner takes a "reasonable salary" (subject to payroll taxes) and receives remaining profits as distributions (not subject to self-employment tax). This can save thousands in SE tax for earners netting over $60K–$80K annually. The trade-off is payroll administration requirements and compliance costs.
📖 Calculator: S-Corp Tax Savings Calculator 2026
C-Corporation
A corporation taxed as a separate entity—the business pays corporate income tax on its profits, and shareholders pay tax again on dividends received (double taxation). Rarely the right choice for solo online earners, but preferred by venture-backed startups because it allows multiple share classes and unlimited shareholders. The 21% corporate tax rate can be advantageous in specific high-reinvestment scenarios.
EIN (Employer Identification Number)
A nine-digit number assigned by the IRS to identify a business entity for tax purposes—essentially a Social Security number for your business. Required to open a business bank account, hire employees, or form an LLC taxed as anything other than a disregarded entity. Applying online at IRS.gov takes 5 minutes and is free. Sole proprietors without employees can use their SSN, but an EIN adds privacy.
Operating Agreement
An internal document that outlines how an LLC is managed, how profits are distributed, how ownership changes are handled, and what happens if members disagree. While not filed with the state, this document is critical for maintaining the LLC's liability protection—without it, a court may treat the LLC as a sole proprietorship. Single-member LLCs should still have one.
Pass-Through Taxation
A tax structure where the business itself does not pay income tax; instead, profits "pass through" to the owner's personal tax return and are taxed at individual rates. Sole proprietorships, LLCs (default), and S-Corps all use pass-through taxation. This avoids the double taxation faced by C-Corporations and is the most common structure for online businesses.
Registered Agent
A person or company designated to receive legal documents (lawsuits, state correspondence) on behalf of your LLC or corporation. Every state requires a registered agent with a physical address in the state of formation. Services like Northwest Registered Agent cost ~$125/year. You can serve as your own registered agent, but a service adds privacy and ensures you never miss a document.
Piercing the Corporate Veil
A legal ruling where a court ignores the LLC or corporate structure and holds the owner personally liable for business debts or judgments. This typically happens when the owner commingled personal and business funds, failed to maintain an operating agreement, used the business as a "personal piggy bank," or committed fraud. Maintaining clean separation of finances is the primary defense.
📖 Protect yourself: Separating Business and Personal Finances
Articles of Organization
The formal document filed with a state to create an LLC. It includes the business name, registered agent information, management structure, and sometimes the business purpose. Filing fees range from $50 (Wyoming) to $800 (California). Once approved, the LLC legally exists and you receive a stamped, official copy from the Secretary of State.
Income & Documentation Terms (8 Terms)
Why this matters: These are the forms and concepts that determine how your income is reported to the IRS—and how you report income paid to others. Mismatched forms are the #1 trigger for IRS notices. See also: 1099-K Reporting 2026 Guide.
1099-K
An IRS information return issued by payment settlement entities (PayPal, Stripe, Venmo, Cash App, Etsy, eBay, Amazon) reporting the gross amount of payment transactions processed for a payee. In 2026, the threshold is just $600 in gross payments—dramatically lower than the old $20,000/200-transaction threshold. The 1099-K reports gross payments, not net income; you must deduct fees, refunds, and business expenses on your tax return to arrive at taxable income.
📖 Complete guide: 1099-K Reporting in 2026
1099-NEC
The form used to report nonemployee compensation—specifically payments of $600 or more made to independent contractors, freelancers, or other non-employees for services performed. If you hire a graphic designer, virtual assistant, or developer as a contractor and pay them $600+, you must issue them a 1099-NEC by January 31 and file a copy with the IRS. See our guide: 1099-NEC vs 1099-MISC.
1099-MISC
A separate information return used for miscellaneous income not covered by the 1099-NEC—including rent payments, prizes and awards, royalties, and certain other payments. Before 2020, nonemployee compensation was reported on Box 7 of the 1099-MISC; the IRS revived the 1099-NEC specifically to separate contractor payments and reduce confusion.
W-9
A form you provide to clients or platforms that collects your name, business name, address, and Taxpayer Identification Number (SSN or EIN). Clients use this information to issue 1099-NECs to you at year-end. As a business owner, you should also collect W-9s from every contractor you pay $600+ so you can issue their 1099s. Keep W-9s on file; do not send them to the IRS unless requested.
W-2
The form employers issue to employees reporting wages paid, taxes withheld (federal income, Social Security, Medicare), and other compensation. Online earners with both a W-2 job and a side business receive W-2s from their employer and must also report side income on Schedule C. If your online business is structured as an S-Corp and you pay yourself a salary, you will receive a W-2 from your own business.
Gross Receipts
The total amount of money your business receives before any deductions—including cash, checks, credit card payments, PayPal and Stripe deposits, and the fair market value of property or services received in barter transactions. Gross receipts go on Line 1 of Schedule C. This is not your profit; it's the starting number from which you subtract all business expenses.
Net Profit (Net Income)
The amount remaining after subtracting all ordinary and necessary business expenses from gross receipts—also called "the bottom line" on Schedule C. This is the number on which both income tax and self-employment tax are calculated. For online earners, increasing net profit is the goal, but maximizing deductions to reduce taxable net profit is equally important.
Schedule SE
The IRS form used to calculate self-employment tax (15.3%) on your net self-employment income. It takes your Schedule C net profit, multiplies by 92.35% (accounting for the employer-equivalent portion), and applies the Social Security and Medicare rates. The result flows to your Form 1040 as both a tax liability and an above-the-line deduction for half the amount.
Banking Terms (10 Terms)
Why this matters: Understanding banking terminology helps you choose the right accounts, avoid hidden fees, and maximize the interest earned on your cash reserves. See our comparison: Best US Banks for Online Entrepreneurs 2026.
ACH Transfer (Automated Clearing House)
An electronic payment between bank accounts processed through the ACH network—used for direct deposits, bill payments, and bank-to-bank transfers. ACH transfers are typically free or low-cost ($0–$3) and take 1–3 business days. Most payment processors (Stripe, PayPal) use ACH to deposit funds into your business bank account. ACH is slower but significantly cheaper than wire transfers.
Wire Transfer
A real-time electronic transfer of funds between banks, processed individually rather than in batches like ACH. Domestic wires typically cost $15–$35 and settle the same day. International wires cost $25–$50 and may take 1–2 days. Wire transfers are irreversible once sent, used for large or time-sensitive payments, and require the recipient's bank routing and account numbers.
FDIC Insurance
Federal insurance that protects depositors up to $250,000 per depositor, per insured bank, per ownership category if the bank fails. This means if your bank goes under, you don't lose your money (up to the limit). Business accounts are typically covered separately from personal accounts at the same bank. Some fintech platforms offer extended coverage through partner bank networks (e.g., Mercury's up to $5M coverage). All banks listed in our best US banks guide are FDIC-insured.
APY (Annual Percentage Yield)
The effective annual rate of return on a savings or interest-bearing account, accounting for compound interest. A 5.00% APY means $10,000 grows to $10,500 in one year if interest compounds. APY is the number to compare when choosing a high-yield savings account—it standardizes comparisons across accounts with different compounding frequencies. In 2026, the best HYSAs offer 4.5–5.2% APY.
📖 Compare rates: Best High-Yield Savings Accounts 2026
HYSA (High-Yield Savings Account)
A savings account offering interest rates significantly higher than the national average (often 10–20x higher than traditional savings accounts). HYSAs are ideal for emergency funds, tax reserves, and business operating cash. They are typically offered by online banks with lower overhead costs and are FDIC-insured. The interest earned is taxable as ordinary income.
Routing Number
A nine-digit code that identifies the specific financial institution where your account is held—used for ACH transfers, wire transfers, and direct deposits. It's the first set of numbers printed at the bottom of a check. Different routing numbers may apply for ACH versus wire transfers even at the same bank, so confirm which one to use for each type of transaction.
Business Checking Account
A bank account specifically designed for business transactions—separate from personal accounts. Essential for maintaining the liability protection of an LLC, simplifying bookkeeping, and presenting a professional image to clients. In 2026, many online business banks (Mercury, Relay, Novo) offer free business checking with no minimum balance and built-in integrations with Stripe, QuickBooks, and other tools. Read: Finance Foundations for Online Earners.
Business Savings Account
An interest-bearing account for holding business cash reserves not needed for daily operations. Used for tax set-asides, emergency reserves, and future investment capital. Many business checking providers also offer savings or treasury products with competitive APY. The Profit First method specifically recommends multiple savings accounts for different purposes.
📖 System: Profit First for Online Businesses
Overdraft
When a transaction exceeds your account balance and the bank covers the shortfall—typically for a fee of $25–$35 per occurrence. Most business banks offer overdraft protection (linking to a savings account or credit line) to prevent declined transactions. Many online-first banks (Mercury, Relay) have no overdraft fees because they simply decline transactions when funds are insufficient.
Minimum Balance Requirement
The lowest amount you must keep in a bank account to avoid a monthly maintenance fee. Traditional banks (Chase, Bank of America) often require $1,500–$5,000 minimum balances to waive $12–$25 monthly fees. Most fintech business banks (Mercury, Relay, Novo) have eliminated minimum balance requirements entirely, making them the preferred choice for new online earners.
Payment Processing Terms (10 Terms)
Why this matters: These terms appear in your processor statements and determine how much of each sale you keep. Understanding them can save 0.5–1% on every transaction. See: Stripe vs PayPal Fees 2026.
Interchange Fee
The fee paid by the merchant's bank to the cardholder's bank for each credit or debit card transaction—set by card networks (Visa, Mastercard) and representing the largest component of processing costs. Interchange rates vary by card type (rewards cards cost more), transaction method (card-present vs card-not-present), and industry. For online businesses, card-not-present interchange rates are typically higher due to increased fraud risk.
Chargeback
A forced reversal of a card transaction initiated by the cardholder's bank, usually because the customer disputes the charge (fraud, product not received, product not as described). Chargebacks incur fees ($15–$25 per occurrence) and count against your dispute ratio. Winning a chargeback requires submitting compelling evidence that the transaction was legitimate. Read our complete guide: How to Win Payment Chargebacks.
Dispute Ratio
The percentage of your total transactions that result in chargebacks, monitored by card networks. Visa and Mastercard typically require a dispute ratio below 0.75–1% of total transactions. Exceeding this threshold can result in fines, increased processing fees, or account termination. Actively monitoring and responding to chargebacks is essential for maintaining your ability to accept card payments.
Payment Gateway
The technology that securely transmits payment information from your website or invoicing system to the payment processor for authorization—essentially the "digital terminal" for online transactions. Stripe, PayPal, Square, and Braintree all function as both gateway and processor (a "full-stack" provider), simplifying setup by eliminating the need to integrate separate gateway and processor services.
Merchant Account
A specialized bank account that holds funds from credit and debit card transactions before they are settled and deposited into your business checking account. Traditional setups require a separate merchant account, but modern processors like Stripe and PayPal handle this behind the scenes as part of their aggregated merchant model—meaning you don't need to apply for a separate merchant account.
Payment Processor
The company that handles the technical processing of card transactions—routing information between the merchant, card networks, and banks. The processor authorizes transactions, settles funds, and manages security compliance. For most online earners, the processor is also the gateway (Stripe, PayPal, Square). Read our Stripe Review 2026 for the most common choice.
PCI Compliance (PCI DSS)
The Payment Card Industry Data Security Standard—a set of security requirements that all businesses accepting card payments must follow to protect cardholder data. Using a hosted payment gateway like Stripe Checkout or PayPal largely offloads PCI compliance to the provider, as card data never touches your server. Handling raw card data on your own server requires significantly more compliance effort.
3D Secure (3DS)
An additional authentication layer for online card transactions that redirects the cardholder to their bank's website to verify identity (via SMS code, biometric, or app approval). For merchants, 3DS shifts liability for fraud-related chargebacks from the merchant to the card issuer—a significant benefit for digital product sellers. Stripe, PayPal, and most major processors support 3DS.
Authorization
The first step in processing a card payment: the processor checks with the cardholder's bank to confirm the card is valid, has sufficient funds, and is not reported stolen. If approved, the funds are "held" (not yet transferred) and the transaction proceeds to settlement. Authorization holds typically expire within 7 days if not captured.
Settlement (Capture)
The second and final step of a card transaction: funds are actually transferred from the cardholder's bank to the merchant's account, typically within 1–2 business days. For Stripe, standard settlement is a 2-day rolling transfer; Instant Payouts (for an additional 1% fee) can move funds to a debit card within minutes. Settlement timing affects cash flow management for online businesses.
📖 Manage cash flow: Cash Flow Management for Online Businesses
Retirement Account Terms (10 Terms)
Why this matters: Self-employed online earners have access to the most powerful retirement accounts available—with contribution limits far exceeding those of W-2 employees. Using the right one can shelter $69,000+ from taxes annually. See: Solo 401(k) vs SEP IRA 2026.
Solo 401(k) (Individual 401k)
A retirement account designed for self-employed individuals with no employees (except a spouse). It allows both "employee" contributions (up to $23,000 in 2026, or $30,500 if over 50) and "employer" profit-sharing contributions (up to 25% of compensation), with a combined maximum of $69,000 for 2026. The Solo 401(k) also offers a Roth option, loan provisions, and higher contribution limits at lower incomes compared to a SEP IRA. The best overall retirement account for solo online earners.
📖 Full comparison: Solo 401(k) vs SEP IRA
SEP IRA (Simplified Employee Pension)
A retirement account allowing employer-only contributions (no employee deferral) of up to 25% of net self-employment income, capped at $69,000 for 2026. SEP IRAs are simpler to set up and administer than Solo 401(k)s—no annual IRS filing required. However, they lack a Roth option and loan provisions. Best for self-employed earners who want simplicity and consistently high income where the contribution difference with a Solo 401(k) is minimal.
Roth IRA
An individual retirement account funded with after-tax dollars—contributions are not tax-deductible, but qualified withdrawals in retirement are entirely tax-free (including all investment growth). Contribution limit is $7,000 ($8,000 if 50+) for 2026, with income phase-outs that limit direct contributions for high earners. The Backdoor Roth IRA strategy allows high-income earners to bypass income limits. See our guide: Roth IRA for Online Earners 2026.
Traditional IRA
An individual retirement account where contributions may be tax-deductible (depending on income and whether you have a workplace retirement plan), investments grow tax-deferred, and withdrawals in retirement are taxed as ordinary income. For self-employed earners with access to a Solo 401(k) or SEP IRA, the Traditional IRA is typically a supplemental account rather than the primary retirement vehicle.
HSA (Health Savings Account)
A tax-advantaged account with a unique triple tax benefit: contributions are pre-tax (or tax-deductible), growth is tax-free, and withdrawals for qualified medical expenses are tax-free. To qualify, you must be enrolled in a High Deductible Health Plan (HDHP). The 2026 contribution limit is approximately $4,150 for individuals and $8,300 for families. Many financially savvy online earners treat the HSA as a supplemental retirement account by paying medical expenses out-of-pocket and letting HSA funds grow invested for decades.
📖 Full strategy: HSA Guide for Self-Employed 2026
Defined Benefit Plan (Cash Balance Plan)
An advanced retirement plan allowing much larger tax-deductible contributions than a Solo 401(k) or SEP IRA—potentially $150,000–$300,000+ annually depending on age and income. These plans are actuarially calculated to fund a specific retirement benefit. High setup and annual administration costs ($1,500–$3,000/year) make them appropriate only for online earners consistently generating $250K+ annually who want to aggressively reduce taxable income.
📖 High-income strategies: Tax Strategy for High-Income Online Earners
Contribution Limit
The maximum amount that can be contributed to a specific retirement account in a given tax year. Exceeding contribution limits triggers IRS penalties (6% excise tax on excess contributions not corrected by the tax filing deadline). Limits are adjusted annually for inflation. Self-employed earners must be especially careful with SEP IRA and Solo 401(k) contribution calculations, as the employer-contribution portion is based on net self-employment income after subtracting half of SE tax.
Required Minimum Distribution (RMD)
The IRS-mandated minimum amount that must be withdrawn annually from tax-deferred retirement accounts (Traditional IRA, SEP IRA, Solo 401k traditional portion) starting at age 73 (in 2026). RMDs are calculated based on life expectancy tables and account balance. Roth IRAs have no RMDs during the owner's lifetime, making them valuable for wealth transfer. Failing to take RMDs incurs a 25% penalty on the amount not withdrawn.
Employer Contribution (Profit-Sharing)
The portion of retirement contributions made by the "employer" side of your self-employed business—in addition to any employee deferrals you make. For a Solo 401(k), this is up to 25% of compensation. For a SEP IRA, it's up to 25% of net self-employment income. This contribution is entirely tax-deductible as a business expense and is one of the most powerful tax reduction tools available to online earners.
Employee Deferral (Elective Deferral)
The portion of retirement contributions you make as an "employee" of your own business—only available in a Solo 401(k), not a SEP IRA. For 2026, the deferral limit is $23,000 ($30,500 if 50+). These can be made on a pre-tax (traditional) or after-tax (Roth) basis, giving you control over whether to reduce current-year taxable income or create tax-free retirement income.
Investment Terms (8 Terms)
Why this matters: Once you're earning and saving, investing is how you grow wealth. These terms cover the fundamentals every online earner should understand before putting money into the market. See: How to Start Investing as a Self-Employed Earner.
Index Fund
A mutual fund or ETF designed to track the performance of a specific market index (like the S&P 500 or total US stock market) rather than trying to beat it through active stock picking. Index funds offer broad diversification at very low cost (expense ratios as low as 0.015%). For online earners investing for the long term, a simple 3-fund portfolio of index funds outperforms most professional money managers. Read: Index Fund Investing for Online Earners.
ETF (Exchange-Traded Fund)
A fund that trades on an exchange like a stock—bought and sold throughout the trading day at market prices rather than priced once daily like mutual funds. Most ETFs are passively managed and track an index, offering low expense ratios and tax efficiency. ETFs can be held in any brokerage account, retirement account, or HSA. Popular ETFs for online earners include VTI (US total market), VXUS (international total market), and BND (total US bond market).
Dividend
A portion of a company's profits paid to shareholders, typically quarterly. Qualified dividends (from US corporations and certain foreign corporations where you've held the stock for over 60 days) are taxed at the lower long-term capital gains rate (0%, 15%, or 20%). Non-qualified dividends are taxed as ordinary income. Dividend income is considered passive for tax purposes but does not reduce self-employment tax.
Capital Gain
The profit realized when you sell an asset (stock, crypto, business) for more than you paid. Short-term capital gains (asset held 1 year or less) are taxed as ordinary income at your marginal rate. Long-term capital gains (asset held over 1 year) enjoy preferential tax rates of 0%, 15%, or 20% depending on income. Selling a profitable online business after holding for 12+ months can save tens of thousands in taxes compared to short-term treatment. See: Passive Income Tax Guide.
Asset Allocation
The mix of stocks, bonds, and cash in your investment portfolio, expressed as percentages (e.g., 70% stocks / 30% bonds). Asset allocation is the primary driver of long-term investment returns and risk level. A common starting point is "your age in bonds" or "120 minus your age in stocks." Online earners with variable income may prefer a slightly more conservative allocation with a larger emergency fund cushion.
Expense Ratio
The annual fee charged by a fund (mutual fund or ETF), expressed as a percentage of assets under management. A 0.10% expense ratio costs $1 per year per $1,000 invested. Over 30 years, the difference between a 0.04% expense ratio (VTI) and a 1.00% expense ratio (actively managed fund) can consume over 25% of your total returns. Index fund investors prioritize low expense ratios above nearly all other fund characteristics.
Compound Interest (Compound Growth)
The process where investment earnings generate their own earnings over time—often called "interest on interest." A $10,000 investment earning 7% annually grows to over $76,000 in 30 years, with only $10,000 being the original principal and $66,000 being compound growth. Starting early is more powerful than contributing more later: the same monthly contribution started at age 25 produces roughly double the retirement balance compared to starting at 35.
Dollar-Cost Averaging (DCA)
Investing a fixed dollar amount at regular intervals regardless of market conditions—buying more shares when prices are low and fewer when prices are high. For online earners with variable income, committing to invest a fixed percentage of each month's income (rather than a fixed dollar amount) automates wealth building. DCA removes the psychological pressure of trying to "time the market" and produces better long-term outcomes for most investors.
Business Finance & Metrics Terms (9 Terms)
Why this matters: These are the numbers that reveal whether your online business is healthy, sustainable, and growing—or running fast toward a cash crisis. See: Financial Ratios Every Online Business Should Track.
Cash Flow
The net movement of cash into and out of your business over a specific period—not the same as profit. A business can be profitable on paper but have negative cash flow (e.g., if clients pay slowly while expenses are due immediately). Cash flow is the lifeblood of an online business; monitoring it weekly prevents the common scenario of running out of operating cash despite having healthy sales.
📖 Manage it: Cash Flow Management for Online Businesses
Accounts Receivable (AR)
Money owed to your business by clients who have been invoiced but have not yet paid—representing revenue earned but not yet received in cash. High accounts receivable relative to revenue signals slow-paying clients and potential cash flow problems. Strategies to reduce AR include requiring upfront deposits, offering early-payment discounts, and setting shorter payment terms. Read: How to Get Paid Faster as a Freelancer.
Accounts Payable (AP)
Money your business owes to vendors, contractors, and suppliers—invoices you've received but not yet paid. Managing AP strategically (paying just before due dates rather than immediately, taking advantage of early-payment discounts when available) improves cash flow. Tracking AP alongside AR gives a complete picture of your business's short-term financial position.
Net Profit Margin
Net profit divided by total revenue, expressed as a percentage—showing how much of each dollar earned becomes profit. A 30% net profit margin means $0.30 of every revenue dollar is profit after all expenses. Healthy digital businesses typically target 25–50%+ net margins; service businesses and agencies may run at 15–25%. Tracking margin over time reveals whether growth is improving or degrading profitability.
📖 Track it: Financial Ratios for Online Businesses
SDE (Seller's Discretionary Earnings)
A measure of a business's total financial benefit to its owner, calculated as net profit plus the owner's salary, personal expenses run through the business, non-essential expenses, and any one-time costs. SDE is the primary valuation metric for small online businesses being sold. Buyers apply a multiple (typically 2–4x SDE for most online businesses) to determine the purchase price. Understanding SDE is essential when preparing to sell. See: How to Value an Online Business for Sale.
EBITDA (Earnings Before Interest, Taxes, Depreciation, and Amortization)
A measure of operating profitability that strips out non-operating expenses (interest, taxes) and non-cash accounting charges (depreciation, amortization). EBITDA is more commonly used for larger businesses ($1M+ revenue) being sold to institutional buyers, whereas SDE is the standard for smaller online businesses. EBITDA multiples for online businesses typically range from 3–8x depending on growth rate, margins, and recurring revenue composition.
Burn Rate
The rate at which a business spends its cash reserves, typically expressed monthly. If your business has $30,000 in the bank and spends $10,000 per month with no revenue, your burn rate is $10,000/month and your runway is 3 months. For online earners investing in growth before profitability, tracking burn rate prevents running out of cash. The goal is to reduce burn rate as revenue scales.
Runway
The number of months a business can continue operating before running out of cash, calculated by dividing current cash reserves by monthly burn rate. A healthy online business should maintain at least 6–12 months of runway given the variable nature of online income. This concept is closely related to the emergency fund—see our Emergency Fund Guide for Online Earners.
Accrual Basis vs Cash Basis Accounting
Cash basis: Revenue is recorded when payment is received; expenses when paid. Simpler and used by most small online businesses. Accrual basis: Revenue is recorded when earned (invoiced), and expenses when incurred (billed), regardless of when cash changes hands. Accrual accounting provides a more accurate picture of business performance but is more complex. Most online earners use cash basis for tax purposes. See: Best Accounting Software for Online Businesses.
How to Use This Glossary
Bookmark this page (Ctrl+D / Cmd+D). Whenever you encounter an unfamiliar term in a tax document, processor statement, or contract, search this page. Each definition links to a deeper guide where available. For the complete framework covering every financial system, see the Complete Finance and Money Guide for Online Earners 2026.
Where to Go From Here
Frequently Asked Questions
A tax deduction reduces your taxable income—a $1,000 deduction saves you $240 if you're in the 24% bracket. A tax credit reduces your actual tax bill dollar-for-dollar—a $1,000 credit saves you $1,000 regardless of your bracket. Credits are more valuable, but deductions are more common. Online earners should prioritize credits first, then maximize deductions. See our full guide to tax deductions.
You report the full $15,000 as gross receipts on Schedule C, then subtract all your business expenses (fees, software, equipment, advertising, etc.) to arrive at your net profit—which is the amount actually taxed. The 1099-K reports gross transactions, not taxable income. Keep detailed records of all expenses. Read our guide: 1099-K Reporting in 2026.
You can use your SSN as a sole proprietor without employees. However, an EIN is free, takes 5 minutes to obtain at IRS.gov, and adds a layer of privacy by keeping your SSN off W-9s you provide to clients. It's also required for opening most business bank accounts. We recommend getting one—it's quick and costs nothing. See our Finance Foundations guide for the complete setup.
The Solo 401(k) lets you contribute more at lower income levels because you can contribute both as an "employee" (up to $23,000) and as an "employer" (profit-sharing). The SEP IRA only allows employer contributions (up to 25% of net income). The Solo 401(k) also offers a Roth option and loans. For most solo online earners, the Solo 401(k) wins. See the full comparison: Solo 401(k) vs SEP IRA.
Most online businesses under $1M in revenue stick with cash basis for its simplicity. Consider switching to accrual if you carry significant accounts receivable (clients take 30+ days to pay), have inventory, or are seeking outside financing where lenders require accrual-based financials. For tax purposes, businesses under $30M in average gross receipts can use cash basis. Read: Best Accounting Software for Online Businesses.
An HSA is technically a health savings account, but financially savvy earners treat it as a supplemental retirement account because of its unmatched triple tax advantage. The strategy: contribute pre-tax dollars, invest them for decades, pay current medical expenses out-of-pocket, save receipts, and reimburse yourself tax-free in retirement. There's no time limit on reimbursements. Full guide: HSA for Self-Employed Online Earners.