USA Tax & Corporate ComplianceThe 2026 Guide

Forming the entity is the easy part. These seven items turn a certificate into an operating company that can bank, hire, invoice and stay in good standing.

Entity choice decides whether profit is taxed once or twice, which return you file, and whether a foreign owner can hold shares at all.

The federal corporate income tax is a flat rate — there are no brackets for C-Corporations.

Deductions worth knowing about

Two provisions restored by the 2025 tax legislation materially change how capital-intensive and R&D-heavy companies compute taxable income: 100% bonus depreciation on qualifying property, and immediate expensing of domestic research and experimental costs rather than five-year amortisation. If you capitalised R&D under the previous rules, ask your accountant whether a catch-up or amended return is available to you.

Federal tax is only half the picture. Each state sets its own corporate rate, and you may owe tax in several states at once depending on where your income is earned.

Franchise tax is a fee for the privilege of existing in a state. It is charged whether or not you made a profit, and whether or not you traded at all. Delaware, Texas, California and Tennessee are the ones founders meet most often.

There is no federal sales tax in the United States. Sales tax is imposed by states, counties and cities, which is why a single order can carry three overlapping rates.

You can owe sales tax in a state you have never visited

Since South Dakota v. Wayfair, physical presence is no longer required. Most states impose an economic nexus threshold — commonly $100,000 in sales or a set number of separate transactions into that state in a year. Cross it, and you must register, collect, file and remit there. Selling through Amazon, Etsy or a similar platform usually shifts collection to the marketplace facilitator, but it does not always remove your own registration or filing duty.

Filing frequency is set by the state based on your volume — monthly, quarterly or annually. Zero-sales periods still require a return in most states.

The moment you have one US employee, payroll becomes your highest-frequency and highest-risk compliance obligation. Deposits are due on a schedule set by the IRS, not by your cash flow.

State payroll taxes

• State income tax withholding — in the state where the employee physically works, which for remote staff is where they sit, not where you are.
• State unemployment tax (SUTA) — rate and wage base vary by state and by your claims history.
• Disability and paid family leave — required in California, New York, New Jersey, Rhode Island, Hawaii and a growing list of others.
• Workers’ compensation insurance — not a tax, but legally mandatory in almost every state from the first employee.

Which form you file follows directly from your entity type and any tax election you have made.

An extension extends the time to file, never the time to pay. Tax owed is still due on the original date, and interest runs from that date regardless of any extension granted.

US tax is pay-as-you-earn. A corporation expecting to owe $500 or more generally makes four instalments during the year rather than settling at the end.

Corporations pay their fourth instalment in December; individuals and pass-through owners pay theirs on 15 January of the following year. When a due date falls on a weekend or public holiday it moves to the next business day. Underpaying triggers an interest-based penalty even if you settle the balance in full at filing.

• Register for federal and state payroll accounts before the first pay run.
• Withhold federal income tax, FICA and applicable state taxes each pay period.
• Deposit payroll taxes on your assigned semi-weekly or monthly schedule.
• File 941 quarterly and 940 annually.
• Issue W-2 to every employee by 31 January.
• Issue 1099-NEC to contractors paid $2,000 or more in 2026, also by 31 January.
• Collect a signed W-9 from every contractor before their first payment — regardless of amount.
• Foreign contractors give you W-8BEN or W-8BEN-E instead, and may require withholding and 1042-S reporting.

Employee or contractor?

Misclassification is one of the most expensive errors a young US company makes, exposing you to back taxes, interest, penalties and wage claims at both federal and state level. Several states apply a strict ABC test that treats a worker as an employee unless you can prove all three conditions. If someone works set hours, uses your tools and takes direction from you, treat them as an employee.

Separate from tax, every state expects you to keep your registration current. These filings are small, cheap and catastrophic to forget.

• Annual or biennial report — confirms officers, addresses and agent. Deadlines vary widely by state.
• Franchise tax return — where the state charges one.
• Registered agent renewal — a lapsed agent means missed lawsuits and default judgments.
• Business licence renewal — city and county licences usually renew annually.
• Foreign qualification maintenance — in every state you have qualified in, not only your formation state.

Falling behind leads to loss of good standing, then administrative dissolution. A dissolved entity cannot enforce its contracts in court, cannot usually close a financing, and reinstatement costs far more than the report ever would have.

This is where most non-US founders get caught. These obligations apply even when the company made no money, had no US bank account and never traded.

Other international filings

The Corporate Transparency Act produced two years of shifting deadlines, injunctions and enforcement pauses. That is settled.

Retention: keep records a minimum of seven years. Employment tax records should be kept at least four years after the tax is due or paid, and anything supporting the cost basis of an asset should be kept for as long as you hold the asset plus the assessment period after you sell it.

Governance is not paperwork for its own sake. Commingling personal and company funds, skipping resolutions for major decisions and letting minutes lapse are exactly the facts a court examines when a creditor asks it to pierce the corporate veil and reach the owners personally.

Calendar-year filers. Dates falling on a weekend or federal holiday generally move to the next business day — though not every state follows that rule, so confirm before relying on it.

US penalties are formula-driven and largely automatic. They accrue whether or not anyone contacts you.

First-time penalty abatement is available to taxpayers with a clean three-year compliance history, and reasonable-cause relief exists for genuine hardship. Neither is automatic — both must be requested, and neither reliably covers international information returns like Form 5472.