Business Tax Deadlines 2027: US and UK Calendar

Missing a tax deadline rarely happens because someone forgot taxes exist. It happens because the dates are scattered across different forms, agencies and countries. This 2027 business tax deadlines calendar puts the key US and UK dates in one place, explains which ones apply to which kinds of business, and gives you a simple tracker so nothing slips through the year.

A glass hourglass with sand running through it, standing on a wooden table in soft light — Tax deadlines arrive at a steady pace. Seeing them all at once is how you stay ahead of the sand.

Key takeaways

January is the busiest month: a US estimated tax payment on 15 January, UK Self Assessment on 31 January and US Forms W-2 and 1099-NEC on 1 February 2027.
US partnership and S-corp returns are due 15 March 2027. Individual and C-corp returns are due 15 April 2027.
US estimated taxes are paid in four installments: 15 April, 15 June, 15 September and 15 January of the following year.
UK payments on account fall on 31 January and 31 July. Other UK dates, such as VAT and Corporation Tax, depend on your own periods.
State, local and payroll deadlines vary, so add your own dates to the calendar template below.

If you run a business in the US or the UK, or you are a freelancer with clients in both, the tax year is a series of checkpoints. Some are fixed national dates that apply to almost everyone. Others depend on your business structure, your accounting period or where you are registered. The trick is to write them all down once, in January, and then let your calendar do the remembering.

A quick note: this article is general information, not tax or legal advice. Deadlines can shift because of weekends, holidays, disaster relief or new legislation, and many depend on your circumstances. Always confirm dates with the IRS, HMRC, your state or local tax agency, or a qualified accountant.

The January rush: three dates in three weeks

The start of 2027 packs several deadlines close together. If you are reading this in the first week of January, these deserve your attention right now.

15 January 2027: US fourth installment of 2026 estimated tax

If you pay US estimated taxes, the final installment for the 2026 tax year is due on 15 January 2027. This covers income you earned toward the end of 2026. Freelancers and owners of pass-through businesses are the people most often affected.

31 January 2027: UK Self Assessment

For UK sole traders, partners and anyone else who files Self Assessment, this is the big one.

31 January 2027 The deadline for the UK Self Assessment online return and any balance due for the 2025/26 tax year, which is also a payment on account date HMRC

If HMRC has asked you to make payments on account, your first payment toward the 2026/27 tax year is generally due on this date as well, on top of any balance for 2025/26. That combination can make January a heavy month for cash, so check your HMRC online account early.

1 February 2027: US Forms W-2 and 1099-NEC

Because 31 January 2027 falls on a Sunday, US Forms W-2 (for employees) and 1099-NEC (for contractors) are due to recipients and filed by 1 February 2027. If you paid contractors last year, gather their names, addresses and tax ID details now so you are not chasing them in the final week.

Pro tip

Set your own internal deadline one week before each official one. Your accountant, payroll provider and contractors all need time, and a week of buffer turns a crisis into a routine.

US federal business tax deadlines for 2027

Here are the main federal dates for a business that uses the calendar year. If your business has a fiscal year that ends in a different month, your return dates move with it, so check the IRS instructions for your form.

15 January 2027: fourth installment of 2026 estimated tax.
1 February 2027: Forms W-2 and 1099-NEC due to recipients and filed.
15 March 2027: partnership returns and S-corp returns for 2026.
15 April 2027: individual returns (including sole proprietors who report business income on their personal return) and C-corp returns for 2026. This is also the first installment of 2027 estimated tax.
15 June 2027: second installment of 2027 estimated tax.
15 September 2027: third installment of 2027 estimated tax.
15 January 2028: fourth installment of 2027 estimated tax. That date falls on a Saturday, so the deadline moves to the next business day. Check the IRS for the exact date.

Extensions are for filing, not paying

The IRS lets most businesses request an extension of time to file a return. In general, though, an extension gives you more time to file the paperwork, not more time to pay the tax. If you expect to owe, estimate the amount and pay by the original deadline to limit interest and penalties. Your accountant can help you decide whether an extension makes sense.

Common mistake

Assuming the S-corp or partnership return can wait until April. Pass-through entities file in March so that owners receive the information they need for their own April returns. If your partnership or S-corp is late, every owner's personal return can be delayed too.

State, local and payroll deadlines

Federal dates are only part of the picture in the US. Depending on where you operate, you may also have:

State income or franchise tax returns, which often follow federal dates but not always.
State estimated tax payments, if your state has an income tax.
Sales tax returns, which may be monthly, quarterly or annual depending on your state and your sales volume.
Payroll tax deposits and quarterly payroll returns, whose schedules depend on how much payroll tax you owe.
Annual reports and franchise taxes for your entity, such as the annual franchise tax Delaware charges companies incorporated there.
Local business taxes or license renewals, set by your city or county.

Rules vary widely, so look up each one on your state and local agency websites or ask your accountant to list them for you. If you use a payroll provider, ask it to confirm which filings it handles and which remain your job.

Close-up of a vintage clock face with Roman numerals and a tiny figure sitting on the edge of the dial — The year moves on whether you are ready or not. A calendar with every deadline keeps you on schedule.

UK business tax deadlines for 2027

UK deadlines split into two groups: fixed dates for Self Assessment, and dates that depend on your own periods for companies, VAT and payroll.

Fixed Self Assessment dates

31 January 2027: online return and balance due for 2025/26, plus the first payment on account for 2026/27 if it applies to you.
31 July 2027: second payment on account for 2026/27. This date falls on a Saturday in 2027, so plan to pay a few days early to be safe.
31 January 2028: the following return and balancing payment, for the 2026/27 tax year.

Dates that depend on your business

Corporation Tax: payment and filing deadlines are set by your company's accounting period, not the calendar year. Check your dates in your HMRC business tax account.
Company accounts and confirmation statement: Companies House sets deadlines based on your incorporation date and accounting reference date.
VAT returns: if you are VAT registered, your return and payment dates follow your VAT periods, usually shown in your HMRC account.
PAYE: employers report payroll to HMRC each time they pay staff and pay over deductions on a regular schedule.

Because these vary from business to business, the best approach is to copy the exact dates from your HMRC and Companies House accounts into your own calendar today.

Build your own 2027 tax calendar

A list in an article is a good start, but your calendar should hold only the dates that apply to you, with reminders that give you time to act. Follow these steps.

List your obligations. Write down every tax you register for or pay: income, corporate, sales or VAT, payroll, estimated payments, annual reports.
Find the exact dates. Use the official sources: IRS, HMRC, Companies House, and your state or local agency.
Add internal deadlines. For each official date, set an earlier date to send records to your accountant or approve a payment.
Set two reminders. One a few weeks out to prepare, and one a few days before to confirm it is done.
Assign an owner. Decide who is responsible: you, your bookkeeper, your payroll provider or your accountant.
Record proof. Save filing confirmations and payment receipts in a single folder for the year.

Tax deadline tracker template

Copy this into a spreadsheet and add a row for each deadline that applies to you. The amounts are made-up examples for illustration only.

Deadline	What is due	Agency	Internal deadline	Owner	Estimated amount (example)	Done?
15 January 2027	2026 Q4 estimated tax	IRS	11 January	Owner	$2,400	Yes
31 January 2027	Self Assessment balance and first payment on account	HMRC	22 January	Accountant	£3,100	No
15 March 2027	S-corp return for 2026	IRS	15 February (records to accountant)	Bookkeeper	Not applicable	No

Add a column for the payment account so you know which bank account needs the cash on each date.

Example

Imagine Tom, a UK-based web developer who also runs a small US LLC with a business partner. His 2027 calendar has the 31 January Self Assessment date, the 31 July payment on account, the 15 March partnership return for the LLC, and his own quarterly US estimated payments. He sets internal deadlines one to two weeks earlier, and moves money into a dedicated tax savings account each month so every payment is covered. The calendar takes him one evening to build and saves him from guessing for the rest of the year.

Plan the cash, not just the dates

Knowing the date is only half of the job. The other half is having the money ready. Look at the deadlines in your calendar and mark the ones that involve a payment. Then work backward:

Estimate each payment with your accountant or from last year's figures.
Divide the total by the months until it is due and set aside that amount each month.
Keep tax money in a separate savings account so it is not mistaken for spending money.
Review the estimates midyear, especially if income has risen or fallen sharply.

Common mistake

Treating January as a one-off. In the UK, a large January bill is often followed by a July payment on account. In the US, the April return date lands on the same day as the first estimated payment for the new year. Plan for the pair, not just the first date.

Your 2027 tax deadline checklist

Confirm whether you owe the 15 January 2027 US estimated payment
Check your UK Self Assessment position before 31 January 2027
Collect contractor and employee details for Forms W-2 and 1099-NEC
Note your 15 March or 15 April federal return date, based on your structure
Add the four 2027 US estimated tax dates or the UK payments on account
Copy Corporation Tax, VAT, Companies House and payroll dates from your accounts
List state, local and sales tax deadlines that apply to you
Set internal deadlines and two reminders for each date
Set aside money monthly for every payment on the calendar

Frequently asked questions

What happens if a US deadline falls on a weekend?

In general, when a federal tax deadline falls on a Saturday, Sunday or legal holiday, it moves to the next business day. That is why the W-2 and 1099-NEC date is 1 February 2027. Always check the IRS for the confirmed date.

Do UK deadlines move if they fall on a weekend?

Do not count on it. Plan to file and pay before any UK deadline that lands on a weekend, and remember that bank transfers can take time to arrive. Check HMRC guidance for the payment method you use.

I live in the UK but earn from US clients. Which calendar applies?

It depends on your residence, your business structure and any US registration. Many UK-based freelancers only deal with HMRC, while someone with a US entity may have deadlines in both countries. A cross-border accountant can confirm what applies to you.

Can my accountant track all these deadlines for me?

Many accountants do, but the responsibility usually stays with you as the taxpayer. Ask exactly which deadlines they cover, and keep your own calendar as a backup.

The bottom line

The 2027 tax year starts fast: 15 January, 31 January and 1 February arrive within three weeks. After that, the rhythm settles into March and April returns, quarterly US estimated payments and the July UK payment on account, with VAT, payroll and company dates set by your own periods.

Spend one evening this week building your personal calendar, adding internal deadlines and setting money aside. Once every date has an owner and a reminder, tax deadlines stop being surprises and become just another part of running your business.