The Small Business Owner Tax Guide

"Small business" is a broad category rather than a precise IRS definition. What matters for tax purposes is your business structure, how your income flows to you, and what obligations that creates. This guide focuses on owner-operated businesses the structures and situations that apply to the vast majority of self-employed professionals and small business owners.

The Tax Common Thread: Pass-Through Entities

Most small businesses operate as pass-through entities. Rather than paying a corporate-level income tax on business earnings, income passes directly through to the owner's personal tax return, where it is taxed at individual income tax rates.

This means:

The IRS taxes the owner, not the business entity: Business profits and losses flow through to Form 1040

No double taxation: Unlike C-Corporations, income is only taxed once at the individual level

Business deductions directly reduce your personal tax bill: Every deductible expense lowers both your income tax and, often, your self-employment tax

Out of scope for this guide C-Corporations are subject to corporate-level income tax (Form 1120) and then shareholder-level tax on dividends a "double taxation" structure. C-Corps are generally not the right choice for owner-operated small businesses. They fall outside the scope of this guide and of Everlance's tools.

Who This Guide Is Written For

This guide is specifically written for:

Sole proprietors and single-person businesses

Single-member and multi-member LLCs

S-Corporations operated by the owner

Partnerships between a small number of active owners

Side businesses, freelancers, and independent contractors scaling toward full-time

Small businesses with one to a handful of employees

If you run an enterprise business, a publicly traded company, or a large corporation, this guide and Everlance's tools are not designed for your scale.

Small business taxes are not a single event they are a set of obligations that recur monthly, quarterly, and annually throughout the year. Understanding what you owe, when, and why is the foundation of staying current and avoiding penalties.

Self-Employment Tax

If you are a sole proprietor, single-member LLC owner, active partner, or S-Corp owner receiving a salary, you pay self-employment tax (SE tax). The rate is 15.3%: 12.4% for Social Security (up to the $176,100 wage base in 2026) and 2.9% for Medicare.

The SE tax is calculated on 92.35% of your net self-employment earnings. You can deduct 50% of the SE tax from your gross income on Form 1040, which reduces your income tax bill. An S-Corp owner pays the equivalent through payroll taxes on their salary; distributions are not subject to SE or payroll taxes.

Federal and State Income Tax

Net business income after deductions is taxed at ordinary federal income tax rates through your personal Form 1040. The rates are progressive 10%, 12%, 22%, 24%, 32%, 35%, or 37% applied to different portions of your taxable income.

State income taxes apply in most states, at rates that vary widely. Some states have flat rates; others have progressive brackets. A handful of states have no personal income tax. Sole proprietors and LLC owners report state business income on their state personal return; S-Corp owners may have additional state-level filing requirements.

Quarterly Estimated Tax Payments

If you expect to owe $1,000 or more in federal taxes for the year, the IRS requires quarterly estimated payments. Missing a deadline triggers an underpayment penalty calculated per quarter.

IRS safe harbor: paying 100% of last year's federal tax (110% if prior-year AGI exceeded $150,000) protects you from underpayment penalties regardless of this year's final bill.

Payroll Taxes (When You Have Employees)

As soon as you hire your first employee, payroll tax obligations begin. These are separate from your own SE tax obligations and require a different set of forms, deadlines, and deposit schedules. A high-level overview follows; see Section 6 for more detail.

FICA (employer share): You pay 7.65% of each employee's wages 6.2% for Social Security and 1.45% for Medicare

Federal income tax withholding: You withhold the employee's federal income tax from their wages and remit it to the IRS

FUTA: Federal Unemployment Tax Act; 6% on the first $7,000 in wages per employee per year (credit reduces effective rate to 0.6% for most employers)

Deposit schedule: Monthly or semi-weekly, depending on payroll tax liability amount

Quarterly reporting: Form 941 is due April 30, July 31, October 31, and January 31

Annual form: Form 940 (FUTA) is due January 31; W-2s must be issued to employees by January 31

Sales Tax Considerations

Sales tax is a state and local obligation, not a federal one. If your small business sells tangible goods or certain services, you may be required to collect and remit sales tax in states where you have nexus (an economic or physical presence). The 2018 Wayfair Supreme Court decision expanded economic nexus rules significantly many states now require sales tax registration once you exceed certain sales volume thresholds, even without a physical location.

Sales tax obligations vary considerably by state, product type, and service category. If you sell physical products or digital goods, confirm your nexus obligations with a CPA or state-specific resource. This guide provides a high-level overview only.

The Annual Filing Deadline

Sole proprietors and single-member LLCs: Schedule C + Schedule SE + Form 1040 by April 15

S-Corp owners: Form 1120-S by March 15 (or September 15 with extension); personal Form 1040 by April 15

Partnerships: Form 1065 by March 15 (or September 15 with extension); partners file personal returns by April 15

All: Extensions are available (Form 4868 for personal; Form 7004 for business returns) but extend the filing deadline only any balance owed is due on the original deadline

ONGOING Monthly Habits

QUARTERLY Before Each Deadline

ANNUALLY Year-End and Filing Season

Track all business income: Record every payment received, from every source, as it arrives

Calculate estimated tax payment: Use YTD net income to estimate your payment; confirm safe harbor minimum

Year-end tax planning (October-November): Final estimate, retirement contributions, deduction timing (see Section 8)

Categorize every business expense: Log and categorize receipts in real time not at year-end

Review YTD income vs. prior year: Identify whether income is running higher or lower than expected

Issue 1099-NECs to contractors: By January 31 for any contractor paid $600+ during the year

Maintain your mileage log: Record every business trip: date, destination, purpose, miles

Pay estimated taxes: IRS Direct Pay or Form 1040-ES by the applicable quarterly deadline

Issue W-2s to employees: By January 31

Reconcile business accounts: Monthly reconciliation prevents errors from accumulating and simplifies quarterly estimates

Payroll tax deposits (if applicable): Deposit employee withholding and employer share of FICA on required deposit schedule

File business returns (if applicable): Partnership Form 1065 and S-Corp Form 1120-S due March 15

File Form 941 (if applicable): Quarterly payroll return due 30 days after each quarter-end

File personal return: Form 1040 with Schedule C and Schedule SE due April 15

File Form 940: Annual FUTA return due January 31

ONGOING Monthly Habits

Track all business income: Record every payment received, from every source, as it arrives

Categorize every business expense: Log and categorize receipts in real time not at year-end

Maintain your mileage log: Record every business trip: date, destination, purpose, miles

Reconcile business accounts: Monthly reconciliation prevents errors from accumulating and simplifies quarterly estimates

QUARTERLY Before Each Deadline

Calculate estimated tax payment: Use YTD net income to estimate your payment; confirm safe harbor minimum

Review YTD income vs. prior year: Identify whether income is running higher or lower than expected

Pay estimated taxes: IRS Direct Pay or Form 1040-ES by the applicable quarterly deadline

Payroll tax deposits (if applicable): Deposit employee withholding and employer share of FICA on required deposit schedule

File Form 941 (if applicable): Quarterly payroll return due 30 days after each quarter-end

ANNUALLY Year-End and Filing Season

Year-end tax planning (October-November): Final estimate, retirement contributions, deduction timing (see Section 8)

Issue 1099-NECs to contractors: By January 31 for any contractor paid $600+ during the year

Issue W-2s to employees: By January 31

File business returns (if applicable): Partnership Form 1065 and S-Corp Form 1120-S due March 15

File personal return: Form 1040 with Schedule C and Schedule SE due April 15

File Form 940: Annual FUTA return due January 31

Two additional tax obligations become relevant as your small business grows: payroll taxes when you hire employees, and sales tax when you sell taxable goods or services. Neither is particularly complex at the small business scale, but both have specific deadlines and forms that require attention.

Your Payroll Tax Responsibilities as an Employer

The moment you hire your first employee, you take on a set of tax obligations as an employer. These are separate from your personal SE tax and operate on their own deadlines:

What you withhold from employee paychecks:

Federal income tax: Based on each employee's W-4 elections and the IRS withholding tables

Employee FICA (Social Security + Medicare): 6.2% Social Security (up to the wage base) + 1.45% Medicare from each paycheck

What you pay as the employer:

Employer FICA: A matching 6.2% Social Security + 1.45% Medicare on each employee's wages

FUTA: Federal Unemployment Tax Act 6% on the first $7,000 in wages per employee annually. If you pay state unemployment tax on time, your effective FUTA rate is typically 0.6%

State payroll taxes: Most states have their own unemployment tax and some have state income tax withholding requirements

Key deadlines and forms:

Tax deposits: FICA and withheld income tax must be deposited on a monthly or semi-weekly schedule based on your payroll tax liability

Form 941 (Quarterly): Reports wages paid and taxes withheld; due April 30, July 31, October 31, and January 31

Form 940 (Annual): Annual FUTA return; due January 31

W-2 forms: Issued to every employee by January 31

1099-NECs: Issued to every contractor paid $600+ by January 31

Pro Tip  Most small business owners with employees use a payroll service (Gusto, QuickBooks Payroll, ADP, or similar) to handle withholding calculations, tax deposits, and quarterly filings automatically. The time saved and reduced error risk are worth the subscription cost for virtually all small businesses.

Sales Tax: State and Local Obligations

Sales tax is not a federal obligation it is administered at the state and local level. If your small business sells taxable goods or services, you may be required to collect sales tax from customers and remit it to the relevant state.

Key things small business owners need to know:

Nexus: You must collect sales tax in any state where you have nexus either a physical presence (office, warehouse, employee) or economic nexus (typically $100,000 in sales or 200 transactions in a state in a year, per the 2018 Wayfair decision)

Product and service taxability: Physical goods are generally taxable; services vary significantly by state. Digital goods have different rules by state.

Registration: You must register for a sales tax permit in each state where you have nexus before collecting tax

Filing frequency: Monthly, quarterly, or annual, depending on your sales volume in each state

Sales tax compliance varies significantly by state, product type, and business model. A CPA or a dedicated sales tax service (Avalara, TaxJar) can help if you sell across multiple states.

October and November are the most valuable tax planning months of the year. You have enough of the year behind you to accurately project your final income, and you still have time to act on moves that could save thousands of dollars. The actions you take before December 31 determine a significant portion of your tax bill not what you do in April.

Run a Final Tax Projection in October or November

Before you can take any meaningful planning action, you need to know where you stand. A year-end projection uses your actual YTD income and expenses to estimate your final tax bill. It answers three critical questions:

How much will I owe? Is your Q4 quarterly payment accurate, or do you need to adjust it upward?

Am I in a higher bracket than expected? Income significantly above what you projected at the start of the year may push you into a higher tax bracket, changing the value of certain deductions.

What actions would reduce my bill? The projection quantifies the tax value of each available planning move retirement contributions, equipment purchases, income deferral so you can prioritize the most impactful actions.

Accelerate Deductible Purchases Before Year-End

For businesses using cash-basis accounting (which includes most small businesses), an expense is deductible in the year you pay it. This creates a real planning window in November and December.

Purchase necessary equipment: Computers, tools, machinery, or other assets needed for the business. Under Section 179, the full cost is deductible in the year of purchase rather than depreciated over time. An item purchased December 31 reduces your current-year taxes; the same item purchased January 1 doesn't help until next year's return.

Prepay business subscriptions and services: Annual software subscriptions, professional memberships, and insurance premiums paid before December 31 are deductible this year. The 12-month rule generally allows prepayment of expenses that cover a period of 12 months or less.

Accelerate other deductible expenses: If you have business expenses you were planning to pay in January, consider paying them in December to shift the deduction into the current tax year.

Cash Basis Caution These strategies apply to cash-basis businesses. If you use accrual accounting, deductions are based on when expenses are incurred, not when they are paid. Confirm your accounting method before planning deductions around payment timing.

Retirement Contributions: The Highest-Value Year-End Move

For profitable small business owners, retirement contributions are typically the single most impactful year-end tax move. Every dollar contributed reduces taxable income dollar-for-dollar, saving you the equivalent of your marginal tax rate on that contribution.

SEP-IRA:

Contribution deadline: Until your filing deadline, including extensions (October 15 with an extension). This makes the SEP-IRA uniquely flexible you can calculate your optimal contribution after seeing your final numbers.

2026 limit: Up to 25% of net self-employment income or $70,000, whichever is less

Simplicity: No plan documents required; open and fund with your brokerage

Solo 401(k):

Deferral election deadline: The plan must exist and the deferral election must be made by December 31 of the tax year

Contribution deadline: Employee deferral contributions can be made until April 15; employer contributions can be made until your filing deadline

2026 limits: Employee deferral up to $23,500; total combined (employee + employer) up to $70,000

Advantage over SEP-IRA: At equivalent income levels, a solo 401(k) allows larger total contributions due to the separate employee deferral component

If you have employees:

SIMPLE IRA: Employee and employer contributions must generally be made within 30 days after year-end

401(k) plans with employees: Plan-specific deadlines apply; your plan administrator will provide them

Planning Example  A small business owner with $120,000 in net income who contributes $22,420 to a SEP-IRA (the maximum at that income level) reduces taxable income by that amount saving approximately $5,600-$7,900 in federal income tax depending on their bracket. This contribution also reduces adjusted gross income, which can affect QBI deduction calculations and other income-sensitive thresholds.

Timing Income: When You Invoice Matters

For cash-basis businesses, income is taxable in the year you receive it not the year you earn it. This creates an opportunity to shift income between tax years in some situations.

Consider deferring a December invoice to January: If this year's income is higher than next year is likely to be, invoicing at the end of December so that payment arrives in January shifts that income to a lower-bracket year. Note: this strategy requires a client willing to pay in January, and it defers it doesn't eliminate the tax.

Conversely, accelerate outstanding income if next year is expected to be higher: If you anticipate higher income next year (a new contract, price increase, business growth), collecting outstanding payments before December 31 locks in this year's lower rate.

Income timing is most valuable when your income genuinely spans a bracket threshold. If your income is solidly within one bracket regardless of timing, the tax impact is minimal.

Reconcile and Organize Before Year-End

Getting organized before December 31 rather than in March ensures you don't miss deductions and makes tax preparation faster and less expensive:

Reconcile all business accounts: Bank accounts, credit cards, and any payment platforms should be reconciled through year-end

Review income against 1099s: Identify clients who paid you $600+ and confirm you have records matching what they'll report to the IRS

Verify expense categories: Review your expense record and confirm deductions are properly categorized

Confirm mileage log is complete: Your business mileage log should be current through December 31. Any gaps are lost deductions.

Gather payroll records: If you have employees, confirm all payroll records are complete and quarterly returns have been filed

Pro Tip  Everlance continuously tracks mileage and categorizes expenses throughout the year. If you've been using it, your year-end records are already organized no December scramble required.

Confirm Your QBI Deduction Before Filing

The Qualified Business Income deduction (up to 23% of net qualified business income) is one of the most valuable available to small business owners and one of the most frequently missed or miscalculated.

Before year-end, confirm:

Whether you qualify: Most sole proprietors and LLC owners below the income phase-out thresholds qualify for the full 23% deduction. Certain specified service businesses face phase-outs above income thresholds.

Whether W-2 wages affect your deduction: For businesses with employees, the QBI deduction may be limited based on W-2 wages paid. In some cases, increasing employee wages before year-end can increase your allowable QBI deduction.

How retirement contributions interact: Retirement contributions reduce net SE income, which reduces the QBI deduction base. The net effect is still favorable in nearly all cases, but a CPA can optimize the interaction.

Was This the Right Year to Change Your Structure?

Year-end is a natural time to evaluate whether your current business structure is still the most efficient one for your income level and risk profile:

If net income exceeded $75,000-$80,000 for the second year in a row: Model the S-Corp election with a CPA. The S-Corp election for the following year must be filed on Form 2553 by March 15 of that year (or within two months and 15 days of the year's beginning).

If you have meaningful personal liability exposure: If you are still operating as a sole proprietor without an LLC, a year-end review is a good time to evaluate whether the liability protection of an LLC is worth the formation cost.

If you brought on partners or co-owners: A multi-member LLC is automatically taxed as a partnership, which requires Form 1065 filing. Confirm your structure reflects your actual ownership arrangement.