Reviewed by the Limited Company Accountant UK team. Figures are for the 2026-27 tax year unless stated.
The Self Assessment deadline for the 2025-26 tax year is 31 January 2027, for both filing your online return and paying any tax owed. Because that date falls on a Sunday, treat Friday 29 January 2027 as your practical cut-off, and start gathering your documents now so you are not scrambling in the final week.
Key takeaways
- The online return and the tax due for 2025-26 are both due by 31 January 2027, which is a Sunday.
- Gather your salary, dividend, benefit and other income records before you start the return.
- You can file as soon as the tax year has ended, so there is no reason to wait for January.
- If you owe tax, the January payment may include your first payment on account for 2026-27.
- File and pay early: penalties and interest start to build the moment the deadline passes.
What is due on 31 January 2027?
Three things typically fall due on 31 January 2027 for a company director. First, your online Self Assessment return for the 2025-26 tax year (6 April 2025 to 5 April 2026) must be submitted. Second, any balancing payment for 2025-26 must reach HMRC. Third, if you are on the payments on account system, the first payment on account for 2026-27 is due the same day.
The date falls on a Sunday in 2027, but HMRC does not extend it. If you pay by bank transfer, allow for processing time, since not all payment methods clear instantly. Aim to have everything done by the end of the previous week.
Step 1: Confirm you can log in
Before anything else, check that you can access your HMRC online account with your Government Gateway user ID and password. If you are new to Self Assessment, you will need your 10-digit UTR and the activation code HMRC posts out. Requesting a replacement can take around 10 working days, and it is the single most common reason directors miss their first deadline.
If you cannot find your UTR, it is printed on previous HMRC letters, or you can find it through your personal tax account. If you need a refresher, our guide to Self Assessment for company directors explains who must file.
Want this handled for you?
Our fixed monthly packages start at £45.83 + VAT and cover accounts, tax and deadlines. Get a free quote or call 0203 4411 258.
Step 2: Gather your records
Collect everything in one folder, digital or paper. For a typical director you will need the following.
- Salary details from your final payslip or P60 issued by your own company.
- Dividend vouchers and board minutes showing how much you were paid and when.
- Any P11D showing benefits in kind, such as a company car or private medical insurance.
- Bank and building society interest statements.
- Details of any personal pension contributions, Gift Aid donations and student loan repayments.
- Rental, freelance or overseas income, if you have any.
- Your company accounts, so your figures are consistent.
Step 3: Reconcile with your company records
The most common cause of errors is a mismatch between what the company says it paid you and what you enter. Compare your dividend vouchers with the director’s loan account and the company bank statements. If you took money out that was not recorded as salary or dividend, it may sit in an overdrawn loan account, which can trigger further tax. Our explainer on Section 455 tax covers that situation.
Step 4: Prepare the return and check the numbers
Work through the online form section by section. The main figures to double-check are total salary, total dividends and any tax already deducted. Then compare the calculated bill against what you expected. If the bill is much higher than you planned, check that you entered dividends in the right box and that the right tax year is selected.
You can sense-check your numbers with the dividend tax calculator, which uses the 2026-27 rates, or the take-home pay calculator to see how salary and dividends combine.
Step 5: File early, ideally by mid-January
There is no benefit to waiting. You can submit your return as soon as the tax year ends, and filing earlier tells you what you owe so you can plan the payment. A sensible internal deadline is 15 January. That leaves two weeks to fix anything that goes wrong, such as a missing document or a login problem.
Step 6: Pay on time
HMRC accepts payment by online or telephone banking, debit card and bank transfer. Use your UTR followed by the letter K as the payment reference if paying by bank transfer, and keep a record of the payment. Do not rely on posting a cheque close to the deadline. If you genuinely cannot pay in full, you may be able to set up a Time to Pay arrangement, but this needs to be requested before or soon after the deadline.
What the January bill usually includes
| Item | When due |
|---|---|
| Balancing payment for 2025-26 | 31 January 2027 |
| First payment on account for 2026-27 | 31 January 2027 |
| Second payment on account for 2026-27 | 31 July 2027 |
Directors who pay themselves mostly in dividends often see a large January bill the first time, because the payment on account is added on top. Read our post on dividend tax rates and how to reduce the bill to plan ahead.
What if you miss the deadline?
If you file late, HMRC applies a £100 penalty automatically, followed by daily penalties after three months and percentage-based penalties at six and twelve months. Late payment adds interest and surcharges. If something unexpected has prevented you from filing, you can appeal on the grounds of a reasonable excuse, but being busy is not enough. File as soon as you can and pay what you owe to limit the damage.
The bottom line
The 31 January 2027 deadline is much easier when you break it into steps: log in, gather records, reconcile, file early and pay on time. Treat 15 January as your own deadline and you will avoid almost every common problem.
Frequently asked questions
When is the Self Assessment deadline in 2027?
31 January 2027 for the 2025-26 return and any tax owed. The date falls on a Sunday, so aim to finish by Friday 29 January at the latest.
Can I file my return before January?
Yes. You can file any time after 5 April 2026 for the 2025-26 tax year, and filing early means you know your bill sooner.
What do I need to file as a company director?
Your UTR, your Government Gateway login, salary and dividend records, details of any benefits and other income, and any reliefs you claim.
How do I pay my Self Assessment bill?
You can pay online, by telephone banking, by debit card or by bank transfer, using your UTR as the reference. Allow time for the payment to clear.
What if I cannot afford to pay in full?
Contact HMRC as early as possible to ask about a Time to Pay arrangement. Interest still applies, but it can avoid enforcement action.
Talk to a limited company specialist
Fixed monthly fees from £45.83 + VAT, no hidden extras. Get a free quote, see our fees or call 0203 4411 258 (Mon-Fri 9:00-17:30).