UK tax deadlines 2026/27: every key date from October 2026 to January 2028

Which Self Assessment dates fall between October 2026 and January 2028?

For the 2025/26 tax year, your online return and any tax you owe are due by 11:59pm on 31 January 2027. Paper returns must reach HMRC by 11:59pm on 31 October 2026. For the 2026/27 tax year, the online return and balancing payment are due by 31 January 2028. These dates apply to sole traders, landlords, company directors and anyone else who files a Self Assessment return.

Sources: GOV.UK on Self Assessment deadlines, registering and payments on account. To pay through your tax code you must owe less than £3,000 and already pay tax through PAYE.

How do payments on account work?

Payments on account are two advance payments towards your tax bill, due by 31 January and 31 July. Each one is usually half of your previous year's Self Assessment bill. You do not have to make them if your last bill was less than £1,000, or if you paid more than 80% of your tax at source, for example through your tax code.

This is why 31 January can be a big day. On 31 January 2027 you may owe the balancing payment for 2025/26 and the first payment on account for 2026/27 at the same time. Making Tax Digital does not change any of these payment dates.

What happens if I miss a Self Assessment deadline?

For 2025/26 returns and payments, the existing penalties apply. A late return gets an initial £100 penalty, then £10 a day after 3 months (up to £900), then the greater of 5% of the tax due or £300 at 6 months and again at 12 months. Paying late adds 5% penalties at 30 days, 6 months and 12 months (GOV.UK: Self Assessment penalties). HMRC also charges interest on late tax from the due date at the Bank of England base rate plus 4% (GOV.UK: HMRC interest rates).

From the 2027/28 tax year, a points-based system for late returns and late payments applies to everyone who files a personal Self Assessment return. If you use Making Tax Digital, it already applies to your 2026/27 return (GOV.UK: MTD penalties). Our personal tax service takes care of the return and the dates for you, and if you are a company director, our guide on how to pay yourself explains how your salary and dividends feed into it.

When are limited company tax deadlines?

Company deadlines run from your own accounting period, not the tax year. A company with taxable profits up to £1.5 million pays its Corporation Tax 9 months and 1 day after its year end. A private company files its accounts at Companies House within 9 months and its Company Tax Return (CT600) within 12 months. The confirmation statement is due at least once every 12 months.

Sources: GOV.UK on starting to do business, paying Corporation Tax, accounts deadlines, Company Tax Returns, confirmation statements and paying in instalments.

What are the deadlines for my year end?

Here is how the rules work out for four year ends, assuming a 12-month accounting period after the company's first accounts.

Notice that the Corporation Tax payment is due before the return. Our free corporation tax calculator gives you an early idea of the bill, so you can set the money aside.

What else should directors watch for?

• Identity verification. Under the transition that began on 18 November 2025, existing directors confirm their identity verification when the company files its next confirmation statement. Companies House will not accept the statement until every director has verified (GOV.UK). UniFi Advisory is registered with Companies House as an Authorised Corporate Service Provider (ACSP), so we can verify directors and people with significant control (PSCs) for you through our Companies House identity verification service.
• Software for the CT600. HMRC's free online filing service closed on 31 March 2026, so Company Tax Returns now have to be filed through commercial software (GOV.UK).
• Late filing penalties. HMRC charges £200 for a late Company Tax Return and another £200 at 3 months late, for returns due on or after 1 April 2026 (GOV.UK). Companies House charges a private company £150 to £1,500 for late accounts, depending on how late they are, and doubles it if accounts are late two years running.
• Director's loan accounts. If you owe your company money at the year end, any section 455 tax is due on the same date as the Corporation Tax, 9 months and 1 day after the year end (CTA 2010 s455).

Our corporation tax and accountancy services cover all of these filings. Setting up a new company? Our guide to setting up a limited company covers the first-year deadlines.

When is my VAT return due?

Your VAT return and payment are due 1 calendar month and 7 days after the end of each VAT period, which is usually a quarter. For a quarter ending 31 December 2026 that means 7 February 2027. The deadline does not move if it falls on a weekend or bank holiday, so allow time for your payment to reach HMRC.

Dates apply GOV.UK's rule to quarters that end on the last day of a month. Sources: GOV.UK on VAT return deadlines, paying by Direct Debit and the Annual Accounting Scheme.

• Direct Debit. HMRC collects the payment 3 working days after the deadline, as long as the Direct Debit was set up at least 3 working days before you submit the return. If you file late, it is taken 3 days after you file.
• Annual Accounting Scheme. You file one return a year, due 2 months after the end of your accounting period, and make advance payments during the year.
• Late returns. Each late return earns a penalty point. Quarterly filers reach the threshold at 4 points: HMRC then charges a £200 penalty, and another £200 for each further late return, including nil returns (GOV.UK).
• Late payment. At the current rates, there is no penalty if you pay within 15 days. After that it is 3% of the VAT owed at day 15, another 3% at day 30, then 10% a year from day 31 (GOV.UK).

Our VAT assistance service can prepare and file your returns, and our free VAT calculator helps with the day-to-day sums.