Self Assessment deadlines 2026/27
Every Self Assessment date between 5 October 2026 and 31 January 2028, the Making Tax Digital quarterly updates, and what each missed deadline costs.
Last updated
Deadlines for the 2025/26 return
| Date | What is due |
|---|---|
| 5 October 2026 | Register for Self Assessment if you started trading (or had other untaxed income) in 2025/26. |
| 31 October 2026 | Paper 2025/26 tax return. |
| 30 December 2026 | Online 2025/26 return, if you are employed, owe under £3,000 and want it collected through your PAYE tax code. |
| 31 January 2027 | Online 2025/26 return. Pay the 2025/26 balancing payment and the first payment on account for 2026/27. |
| 31 July 2027 | Second payment on account for 2026/27. |
Not sure what 31 January and 31 July will cost? Enter last year's bill in our payments on account calculator.
Deadlines for the 2026/27 tax year
| Date | What is due |
|---|---|
| 5 April 2027 | The 2026/27 tax year ends. |
| 5 October 2027 | Register for Self Assessment if you started trading in 2026/27. |
| 31 October 2027 | Paper 2026/27 tax return. |
| 31 January 2028 | Online 2026/27 return (or MTD final declaration) and the 2026/27 balancing payment. |
Making Tax Digital quarterly dates for 2026/27
Making Tax Digital for Income Tax applies to sole traders and landlords whose qualifying income (gross self-employment and property income, before expenses) is over the threshold for the year. It phases in:
- From 6 April 2026: qualifying income over £50,000 in the 2024/25 tax year.
- From 6 April 2027: qualifying income over £30,000 in the 2025/26 tax year.
- From 6 April 2028: qualifying income over £20,000 in the 2026/27 tax year.
Not sure which applies to you? Our Making Tax Digital checker gives your start date and first quarterly deadline from one figure.
If you are in scope for 2026/27 (over £50,000), you keep digital records and send four quarterly updates from compatible software:
| Due | Update |
|---|---|
| 7 August 2026 | Quarterly update for 6 April to 5 July 2026. |
| 7 November 2026 | Quarterly update for 6 July to 5 October 2026. |
| 7 February 2027 | Quarterly update for 6 October 2026 to 5 January 2027. |
| 7 May 2027 | Quarterly update for 6 January to 5 April 2027. |
| 31 January 2028 | Final declaration for 2026/27, which replaces the tax return. |
Quarterly updates are summaries, not payments: the payment dates stay 31 January and 31 July. You can choose calendar quarters (ending on the last day of June, September, December and March) instead; the due dates stay the same. If you are in scope, late quarterly updates and a late final declaration fall under HMRC's points-based penalty system instead of the fixed £100 and daily penalties below, and late tax under its newer late-payment penalties. The exception: HMRC has said it will not give penalty points for late quarterly updates in 2026/27, the first MTD year.
Penalties for missing the 31 January deadline
- 1 day late: £100 fixed penalty, even if you owe no tax.
- 3 months late: £10 a day for up to 90 days (up to £900) on top of the £100.
- 6 months late: a further £300 or 5% of the tax due, whichever is higher.
- 12 months late: another £300 or 5%, and more if HMRC decides you deliberately held back information.
Paying late is penalised separately: 5% of the unpaid tax at 30 days, again at 6 months and again at 12 months. Interest runs daily from 1 February at the Bank of England base rate plus 4%. A late payment on account is charged interest but not the 5% penalties.
When to register
Register by 5 October after the end of the tax year you started trading in: 5 October 2026 if you started in 2025/26, 5 October 2027 if you start in 2026/27. Register online at gov.uk; your Unique Taxpayer Reference (UTR) arrives by post, usually within a couple of weeks, and you need it to file. If you already have a UTR from an earlier return, you keep it, but you still need to tell HMRC you have started trading, or reactivate your Self Assessment record if you stopped filing.
If you cannot pay in full
If you owe £30,000 or less, have filed your latest return, have no other payment plans or debts with HMRC and are within 60 days of the payment deadline, you can set up a Time to Pay plan online and spread the bill over monthly instalments. Interest still runs, but a plan agreed before the 30-day mark avoids the first late-payment penalty. Above £30,000, call HMRC's Payment Support Service.
Reasonable excuses
HMRC can cancel a late-filing penalty if you had a "reasonable excuse": typically serious illness, a bereavement, or a fire or flood that destroyed your records. Forgetting, leaving it to your accountant, or not understanding the system do not count. Appeal within 30 days of the penalty notice.
Know what 31 January costs you - long before 31 January
A deadline only hurts when the number behind it is a surprise. Invoice through this site and your income tax and National Insurance estimate updates as you get paid, on the same HMRC rates as the calculator here. It is an estimate before expenses, and before any payments on account HMRC asks you for.
- Send a clean, numbered invoice in about a minute - VAT handled per line if you are registered, PDF at the end.
- A live set-aside figure for the tax on what you have actually been paid, so the balancing payment is money you have already put by.
- Every invoice, payment and due date in one place when the return is due.
No password and no card. Enter your email, click the link we send, and you are in.
Frequently asked questions
When is the Self Assessment deadline for the 2025/26 tax year?
The online return for 2025/26 is due by 31 January 2027, and so is the tax: the balancing payment for 2025/26 and, if you make payments on account, the first one for 2026/27. A paper return is due earlier, by 31 October 2026.
When are payments on account due?
On 31 January and 31 July. For the 2026/27 tax year the first is due on 31 January 2027 and the second on 31 July 2027, each half of your 2025/26 bill, unless that bill was under £1,000 or more than 80% of your tax was collected at source.
What happens if I miss the 31 January deadline?
A late return gets a £100 penalty straight away, even if you owe no tax. After 3 months HMRC adds £10 a day for up to 90 days, then £300 or 5% of the tax due at 6 months and again at 12 months. Paying late adds interest from 1 February and a 5% penalty at 30 days, 6 months and 12 months.
When do I need to register for Self Assessment?
By 5 October after the end of the tax year in which you started trading. If you started in 2025/26, the deadline is 5 October 2026; if you start in 2026/27, it is 5 October 2027. Register late and you still have to file and pay by 31 January.
Do I need to send Making Tax Digital quarterly updates in 2026/27?
Only if your qualifying income (self-employment and property income before expenses) in the 2024/25 tax year was over £50,000. If so, quarterly updates for 2026/27 are due on 7 August 2026, 7 November 2026, 7 February 2027, 7 May 2027, and the final declaration replaces the tax return on 31 January 2028. Payment dates do not change.
Can I pay my Self Assessment bill in instalments?
Yes. If you owe £30,000 or less, have filed your latest return, have no other payment plans or debts with HMRC and are within 60 days of the payment deadline, you can set up a Time to Pay plan online. Interest still runs on the unpaid tax, but a plan agreed before the 30-day mark avoids the first late-payment penalty.
Tools sole traders use
Accounting software that keeps your records ready for Self Assessment and Making Tax Digital.
- Xero - Online accounting with bank feeds and invoicing, widely used by UK accountants.
- QuickBooks - Bookkeeping and invoicing software with features for sole traders.
- Sage Accounting - UK accounting software for invoices, expenses and VAT returns.
Affiliate links: we may earn a commission if you sign up, at no extra cost to you.
Sources
Related guides
- Payments on account calculator: what you owe on 31 January and 31 July, and why the first bill is about 150% of one year's tax.
- Class 2 and Class 4 National Insurance: the NI you pay alongside income tax through Self Assessment.
- Reduce your tax bill legally: the HMRC-approved levers, ordered by how much they move the bill.
- Allowable expenses: what to deduct before you file.
- Making Tax Digital checker: whether MTD for Income Tax applies to you, and from when.
- Making Tax Digital for Income Tax explained: what it is, who it covers and the timeline.
- MTD quarterly updates: what each update contains and your first deadline.
- Preparing for Making Tax Digital: a six-month plan before your start date.
Or see the full bill for your profit: £30,000 self-employed, £50,000 self-employed, £75,000 self-employed, or browse all bracket pages.