Money dates for US online stores, 2026 and 2027

Federal estimated tax due dates

Tax on store profit is not taken out for you, so the IRS asks for it in four parts during the year. Each date covers the months before it.

When a date lands on a Saturday, Sunday or legal holiday, a payment made the next business day is on time. You can skip the January 15, 2027 payment if you file your 2026 return by February 1, 2027 and pay everything you owe with it. Pay online through your IRS account, Direct Pay or EFTPS.

Sources: IRS, estimated tax due dates, Form 1040-ES (2026), IRS, ways to pay.

Who usually needs to pay estimated tax

You generally need to pay during the year if you expect to owe $1,000 or more when you file, after what is withheld and your credits. A store that makes a profit with no tax taken out of it is the usual case. If you also have a job, asking it to withhold more from your paycheck can cover the store instead.

A quick check. If you answer yes to all three, the dates above are probably for you:

1. Has your store made a profit this year, after product costs, ads, apps and fees?
2. Is nothing being withheld to cover the tax on it?
3. Do you expect to owe $1,000 or more when you file?

Source: IRS, estimated taxes.

Self-employment tax

Profit from a store you run yourself owes self-employment tax on top of income tax. It is Social Security and Medicare for people who work for themselves: 15.3% (12.4% Social Security and 2.9% Medicare), worked out on 92.35% of your net profit. You owe it, and must file, once that comes to $400 or more in a year. It goes on Schedule SE with your Form 1040, and the profit itself on Schedule C.

• The Social Security part stops at $184,500 of combined wages and self-employment earnings in 2026. The 2027 figure is announced by the Social Security Administration in mid-October 2026.
• You can deduct the employer half of it when you work out your adjusted gross income.
• An extra 0.9% Medicare tax applies above $200,000 for a single filer ($250,000 married filing jointly).

An example with a round number, not anyone’s store: $10,000 of profit, times 92.35%, times 15.3%, is about $1,413 of self-employment tax, before any income tax.

Sources: IRS, self-employment tax, IRS, self-employed tax center, Form 1040-ES (2026) worksheet, SSA, contribution and benefit base.

The safe harbor: paying enough to avoid a penalty

Paying too little during the year can bring an underpayment penalty. You avoid it if any one of these is true:

• You owe less than $1,000 when you file.
• You paid at least 90% of this year’s tax during the year.
• You paid at least 100% of last year’s tax, or 110% if last year’s adjusted gross income was over $150,000 ($75,000 married filing separately).

Last year’s tax is the easy one to use, because you already know it: divide it by four and pay a part on each date. A first year with a store, when profit is hard to guess, is when that helps most.

Sources: IRS, underpayment of estimated tax penalty, Form 1040-ES (2026).

Form 1099-K: what it is and when it comes

Form 1099-K reports the payments you received for goods during the year. The company that processed your card payments, a payment app, or the marketplace you sold on sends it to you and to the IRS. It must reach you by January 31.

• Card payments from customers are reported whatever the amount or the number of payments.
• Payment apps and online marketplaces report you when you got over $20,000 in more than 200 payments. The One, Big, Beautiful Bill of 2025 brought this line back to what it was before 2021, as the IRS confirmed in October 2025. They can still send one below it.
• It shows the money that came in, before refunds, fees and product costs. It is not your profit, and you report your income whether or not a form arrives.

Sources: IRS, understanding your Form 1099-K, IRS news release IR-2025-107.

State sales tax for online sellers

Sales tax is set by each state, not by the IRS. As a seller you may have to collect it from customers and pay it to the state.

• Your home state. Where you live and work you have a physical presence, which usually means registering and collecting there no matter how much you sell.
• Other states (economic nexus). Since the Supreme Court’s Wayfair decision on June 21, 2018, a state can make you collect its sales tax once your sales into it pass a line, even with no office there. Most states with a sales tax use $100,000 a year; California and Texas use $500,000, and New York $500,000 with more than 100 sales.
• Marketplace or your own store. When you sell through a marketplace, most states make the marketplace (the “marketplace facilitator”) collect and pay the tax on those sales. On your own store, collecting is yours to do wherever you have to. Some states count your marketplace sales toward their line and some do not.

Each state’s own tax site has the final word. The state chart linked below lists every state’s line and links to its site.

Sources: Streamlined Sales Tax Governing Board, remote sellers, state by state thresholds, marketplace sellers.

Keeping records

Keep whatever shows your income and your costs: payouts and order exports from your store, supplier invoices, ad receipts, app and software bills, and any 1099-K. Any system works as long as it clearly shows income and expenses. Keep them for at least 3 years after you file, and 6 years if you left out more than 25% of your income.

Sources: IRS, recordkeeping, IRS, how long to keep records.

FAQ

Checked October 2026 against the sources linked above. Check with a tax professional. This isn’t tax advice.