UK tax year dates: the key deadlines for businesses

The UK tax year starts on 6 April and ends on 5 April the following year. Those are the tax year dates that Income Tax and Self Assessment work to, so they matter most to sole traders, partners and directors who send a personal tax return.

To work out which tax year a date falls in, compare it with 6 April, not 1 January. A date on or after 6 April belongs to the tax year that starts that day. A date between 1 January and 5 April belongs to the tax year that started the previous April.

Limited companies are different. Corporation Tax, a company’s accounts and its VAT returns each run on their own period, so a company can have several deadlines in a year and none of them on 5 April.

The key dates are set by rules, so they fall on the same day each year or the same distance from the end of your own period. The table gives each rule as GOV.UK states it.

Self Assessment has three main deadlines after each tax year ends: tell HMRC by 5 October if you need to send a return for the first time, file a paper return by 31 October, or file online by 31 January. The tax itself is due by 31 January as well.

• The online return and the payment are both due by 11:59pm on 31 January.
• If you want HMRC to collect the bill through your PAYE tax code, the online return has to be in by 30 December.
• HMRC says you could get a penalty if you tell it after 5 October that you need to send a return.

Many business owners also make payments on account, which are payments towards the next tax bill. They are due on 31 January and 31 July, and each is usually half of the tax you owed for the previous year. Any balance is due by the following 31 January.

You do not make payments on account if your last Self Assessment bill was less than £1,000, or if more than 80% of the tax you owed was already paid outside Self Assessment, for example through a tax code.

Corporation Tax is due 9 months and 1 day after the end of the company’s accounting period, where taxable profits are up to £1.5 million. The date depends on your own year end, not on the 6 April tax year.

The accounting period is the time covered by the Company Tax Return. It cannot be longer than 12 months and is normally the same as the financial year in the company’s annual accounts. The return is due 12 months after the period ends, so the tax has to be paid before the return has to be filed.

A company whose profits are at an annual rate of more than £1.5 million pays in instalments. For a 12-month accounting period the first of four instalments falls 6 months and 13 days after the period starts, which is before the year is over.

Corporation Tax rates are set for financial years that start on 1 April. If an accounting period straddles two financial years with different rates, the tax is worked out on the number of days that fall in each. Our guide on how to pay Corporation Tax covers the payment methods and the reference to use.

A VAT return and the payment are usually due one calendar month and 7 days after the end of the VAT accounting period. The deadline is shown on the return, and the payment has to reach HMRC’s account by then.

VAT periods are your own, so they do not have to line up with the tax year or with your company’s year end. Businesses on the Annual Accounting Scheme and those that must make VAT payments on account have different dates. The methods and how long each takes are in our guide to paying a VAT bill.

Employers pay HMRC what they owe for PAYE by the 22nd of the month, or by the 19th if paying by post. If you usually pay less than £1,500 a month, you may be able to pay quarterly instead of monthly.

The tax year end on 5 April brings a set of payroll dates of its own:

• Send the final payroll report of the year on or before your employees’ payday.
• Update employee records and payroll software for the new tax year from 6 April.
• Give each employee a P60 by 31 May.
• Report expenses and benefits by 6 July.
• Pay Class 1A National Insurance on benefits by 22 July, or 19 July by post.

A private limited company files its annual accounts with Companies House 9 months after its financial year ends. A new company’s first accounts are due 21 months after the date it was registered.

Every company, including a dormant or non-trading one, must also file a confirmation statement at least once a year. You can file it up to 14 days after the review period ends, and the fee is £50 online or £110 on paper as of October 2026. Companies House says that failing to file can lead to a financial penalty and to the company being struck off.

These are separate from the tax deadlines. Filing accounts with Companies House does not file the Company Tax Return with HMRC, and each has its own date.

Making Tax Digital for Income Tax is being phased in by qualifying income, which is income from self-employment and property. It started on 6 April 2026 for people above the highest threshold and reaches lower incomes over the next two years.

HMRC’s guidance on GOV.UK, listed in the sources below, sets out who is in scope and what counts as qualifying income.

Missing a deadline usually costs money: HMRC may charge interest on tax paid late, and late returns can bring penalties. HMRC’s late payment interest rate is set at the Bank of England base rate plus 4 percentage points, so it moves when the base rate does.

The penalty rules differ for each tax, so check GOV.UK for the one that applies. If you cannot pay in full, you may be able to set up a payment plan with HMRC and pay in instalments, once HMRC has checked the plan is affordable. Our guide to HMRC Time to Pay explains how to ask.

Some businesses borrow to meet a bill on the day and repay monthly. A loan adds interest and fees to tax you already owe, so compare its total cost with a payment plan first. The guides to VAT loans and Corporation Tax loans set out that comparison.

Capzy is a credit broker, not a lender, and is paid by the lender. We do not file returns, deal with HMRC for you or give tax advice.

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