When is the Self Assessment deadline?

One of the most important dates to remember if you’re self-employed or run your own business is the Self Assessment deadline. Your tax return shows your income and expenditure for the previous tax year and is how your tax bill is calculated.

If you’re a sole trader or in a business partnership, or if you’re a company director, then you’ll need to file a tax return to HMRC every year. Landlords earning money from renting out property may also need to complete a Self Assessment, but we have a separate guide for that.

When is the Self Assessment deadline?

The Self Assessment tax return deadline is on 31 January each year. This means that the deadline for filing your 2024-25 taxes is by 11.59pm on 31 January 2026. This is also the deadline for paying any tax owed for the previous tax year (and your first instalment of payment on account).

Remember, this deadline is if you choose to file your taxes online – there’s a different date to remember if you want to file a paper return.

There are other important company and self-employed tax return dates too – keep reading and mark your diary with the key tax year dates to remember.

Self Assessment tax – when to file?

Now you’ve got the dates for your diary, make sure you follow the steps to filing your Self Assessment tax return. And wondering how much tax you’ll pay? Read our guide to income tax.

Do I need to pay tax through Self Assessment? 

Yes, if you’re:

• self-employed with earnings over £1,000 in one tax year
• in a business partnership
• you have income from renting out a property
• you claimed Child Benefit when you or your partner earned more than £50,000 a year

There are other reasons too, so have a read of our guide to registering for Self Assessment to check if the Self Assessment deadline applies to you. HMRC has a checker tool you can use if you’re not sure you need to complete a tax return for the 2024-25 tax year. 

Tax return deadlines and dates for small businesses

Key Self Assessment deadlines:

• Self Assessment deadline 2024-25
• Self Assessment deadline 2023-24
• Self Assessment deadline 2025-26

Other tax dates and deadlines:

• Tax year dates
• Deadline for registering for Self Assessment
• Paper tax return deadline
• Tax return deadline for tax collected via PAYE
• Payment on account tax deadline
• Tax year dates for VAT
• Tax year dates for PAYE and National Insurance contributions

The deadline for Self Assessment 2024-25

You can file your tax return at any time before the deadline. In fact, 299,419 people filed their 2024-25 Self Assessment in the first week of the new tax year, according to HMRC.

There are a number of benefits in filing it early. It can make it easier to plan your finances, plus help you minimise the risk of fines. Here are five reasons to do your tax return early.

Under current rules, you’ll need to register for Self Assessment and file your tax return if you earn more than £1,000 from your business. This threshold will increase to £3,000 before the end of this parliament in 2029, meaning thousands of businesses will benefit from not having to file each year. 

The deadline for Self Assessment 2023-2024

If you’ve missed this filing deadline you’ve probably already received a fine. But the fines keep piling up the longer you delay, so it’s important to file your tax return and pay any tax owed as soon as possible.
If you need a hand, check out our ultimate guide to completing a Self Assessment tax return.

The deadline for Self Assessment 2025-2026

We know 2027 may sound like a long way off, but it’s a good idea to start thinking about your tax return as soon as you start earning money. For example:

• consider opening a business bank account to keep business and personal finances separate
• keep all your receipts for tax deductible expenses
• use an accounting app or a spreadsheet to keep track of your income, which should make everything much easier when it comes to filing your tax return
• follow our bookkeeping tips to keep your accounts in order

Tax year dates

We’re currently in the 2025-26 tax year, and from 6 April 2026 we’ll be in the 2026-27 tax year.

Making Tax Digital will be phased in from April 2026, replacing the annual Self Assessment process with quarterly tax returns. These will have to be filed online using HMRC approved software.

When does the tax year end?

The UK tax year ends on 5 April each year.

The end of the tax year is one of the most important tax dates in the calendar. That’s because rates and allowances usually change each year.

For example, the amount you can save in an ISA resets each tax year. If you don’t use your allowance, you lose it. This means it’s important to contribute as much as you can before the new tax year starts.

When does the new tax year start?

The new tax year starts on 6 April each year.

The start of the tax year is often when new tax rules and regulations are introduced.

Paper tax return deadline

The HMRC Self Assessment deadline is 31 October if you want to file a paper return rather than filing online. However, most businesses find it easier to file their tax return online – and under Making Tax Digital plans, paper filing soon won’t be an option.

Tax return deadline for tax collected via PAYE

The deadline for filing your online tax return if you want the tax owed to be collected through PAYE via your tax code is 30 December.

This is only an option if you have some income that’s already taxed through PAYE (as in, you’re employed as well as self-employed), and if your Self Assessment tax bill is below £3,000. See our article on tax codes for more information.

Payment on account tax deadline

Payment on account is due in two instalments across the year – it’s how you pay your tax bill to HMRC. The first payment is due on 31 January and the second payment on account deadline is 31 July.

Payment on account applies to you if your Self Assessment tax bill was more than £1,000 when you submitted your tax return for the period.

It doesn’t apply if your tax bill was less than £1,000, or if 80 per cent or more of your tax was deducted at source (for example through your tax code, or because your bank has deducted interest on your savings). Take a look at our payment on account guide if you’re not sure.

Tax year dates for VAT

If you’re VAT-registered then you’ll need to account for VAT when declaring your income on your Self Assessment tax return. 

All VAT returns must be filed online (unless you have an exemption from Making Tax Digital). This means you’ll need to use accounting software to keep digital records and submit VAT returns.

Our guide to filing and paying VAT explains everything you need to know.

Wondering how much VAT to charge on your products or services? Use our guide to working out VAT to help you.

Tax year dates for PAYE and National Insurance contributions

Monthly PAYE and Class 1 NIC payments – if you’re paying PAYE and Class 1 NICs monthly by an electronic method, payment must reach HMRC by the 22nd of each month. If you’re paying by cheque, payment must reach HMRC by the 19th of each month.

Quarterly PAYE and Class 1 NIC payments – you may be able to pay quarterly if you pay less than £1,500 a month. If you’re paying quarterly, you must pay by the 22nd after the end of the relevant quarter. You should speak to HMRC to find out whether you’re eligible.

Class 1A NIC payments – if you’re paying Class 1A NICs electronically, payment must reach HMRC by 22 July. If you’re paying by post, payment must reach HMRC by 19 July.

For a full list of important business dates to remember, see our key dates guide.

Getting help from HMRC

If you’re confused about the Self Assessment deadline or any other tax year dates, make sure you speak to HMRC to avoid mistakes and late payment penalties. If you need more time to pay your tax bill, you might be able to set up a time to pay plan. 

You can use HMRC’s digital assistant to get help with your tax return online. It’s also possible to call or write to HMRC if you need extra support, but waiting times can be slow.  

If you’re still unsure, you might want to consider hiring an accountant.

Related guides for small business owners

• How long do you need to keep tax records?
• Self-employed tax brackets: thresholds, rates, and allowances
• Your complete guide to business tax
• What type of business insurance do I need?