TL;DR
- 31 January 2026 is the absolute deadline for BOTH filing AND payment31 Jan 2026
- Late filing penalty: £100 minimum. Late payment: 8.75% interest plus 5% penalties£100+
- You must file if you had dividends, salary over £12,570, rental income, or capital gainsMust file
- Cannot pay? Ring HMRC BEFORE the deadline to arrange Time to Pay0300 200 3310
💡Quick reference summary. Continue reading for comprehensive analysis and context.
Quick Summary: What You Need to Know
Key Dates You Cannot Miss
The 31 January deadline is not a gentle suggestion. Here's what happens if you miss it.
31 January 2026 is the last day to file your self-assessment online AND make your full payment. Miss either one and penalties start immediately.
Late Filing and Payment Penalties
Real Example: £5,000 Tax Bill, 6 Months Late
That's nearly 30% extra just because you procrastinated. File on time.
Do You Actually Need to File?
Not every director needs to file. Here's how to know.
You Must File If...
- You received any dividend income (even £1)
- Your salary was over £12,570
- You had bank interest over £500
- You had rental income
- You made capital gains
- You're claiming tax relief
You Might Not Need to File If...
- Salary under £12,570 was your only income
- AND HMRC has not asked you to file
When in doubt, file anyway. The downside of filing when you did not strictly need to is zero. The downside of not filing when you should have is £100 minimum.
What to Include in Your Return
Directors often declare income in the wrong section, which flags their return for enquiry. Here's what goes where.
Common Errors That Trigger Enquiries
Dividend income in the employment section triggers enquiries. Income in the wrong tax year triggers enquiries. Just get it in the right place.
Documents to Gather Before You Start
Do not start your return until you have these.
Your Document Checklist
From your company:
- P60 (salary and tax deducted)
- Dividend vouchers for each dividend paid
- P11D form (if applicable)
From your bank:
- Statements showing interest received
- Total interest for tax year (6 April 2024 to 5 April 2025)
From HMRC or previous records:
- SA302 (if under a Time to Pay arrangement)
- Previous year's return reference
- Pension contribution statements
- Gift Aid receipts
Pro tip: Most directors get stuck here because their accountant has the P60 and dividend vouchers but has not sent them yet. Email your accountant today if you have not got them. Do not wait until 25 January.
Don't want to deal with self assessment yourself?
Book a free 15-minute call with a chartered accountant who can handle your tax return for you.
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Common Mistakes That Trigger HMRC Enquiries
These are the patterns that make HMRC's systems flag your return for manual review.
Dividend Errors (Most Common)
- Claiming dividend income in the wrong tax year (April to April, not January to December)
- Declaring dividends without matching dividend vouchers
- Missing small dividends (HMRC has records from your company)
Employment Section Errors
- Salary figure does not match your P60
- Tax already paid does not match your P60
Missing Income
- Not declaring all bank accounts
- Forgetting about interest or premium bonds
- Other sources like rental or freelance income
The good news: most of these are just administrative. If you catch them, you can amend your return before filing. If HMRC catches them, you will get an enquiry letter 6 to 12 months later, which is annoying and more expensive to fix.
Payment Options and Spreading the Cost
If you cannot pay in full by 31 January, you have options. The key is doing something before the deadline, not after.
Your Payment Options
Pay in Full by 31 January
Cleanest option. No interest, no penalties, no stress.
Time to Pay Arrangement
Ring HMRC Self Assessment on 0300 200 3310 before 31 January. They will negotiate a payment plan, usually 3 to 6 monthly instalments. You will pay interest, but no late payment penalty.
Budget Payment Plan
If this is a recurring problem, set up automatic payments throughout the tax year. Less stressful than one lump sum in January.
Coding Out
For smaller amounts (up to about £3,000), HMRC can adjust your PAYE coding in the next tax year to recover it gradually.
Do Not Ignore It
The worst thing you can do is neither pay nor arrange Time to Pay. You will get a penalty automatically. Ring HMRC before the deadline, even if you have no idea how you will pay.
What to Do If You Cannot File in Time
Filing late costs money. But the hierarchy is clear: file late is better than do not file at all, which is better than file late and do not pay.
If You Are Going to File Late
- 1File anyway, as close to the deadline as possible. Even 1 day late is better than 1 week late.
- 2Include a reasonable excuse letter explaining why (illness, bereavement, accountant delay). HMRC sometimes accepts these.
- 3Pay what you owe as soon as possible.
- 4Appeal within 30 days if you have a strong excuse for the delay.
Need professional help urgently? Most accountants have January rush protocols. Ring your accountant now if you think you will need help. Do not wait until 25 January.
Frequently Asked Questions
What if I filed last year but my circumstances have not changed?
You still need to file. HMRC expects a return every year once you are in the self-assessment system. If you genuinely do not need to file, you can request to be taken out of self-assessment, but this takes time and you should not assume it will happen before the deadline.
Can I estimate figures if I do not have exact numbers?
Yes, but mark them as estimates. HMRC would rather have an estimated return filed on time than an exact return filed late. You can amend the return later if the figures change. Do not deliberately underestimate to reduce your tax bill.
What counts as a reasonable excuse for late filing?
HMRC accepts serious illness, bereavement of a close family member, fire or flood, and sometimes delays caused by HMRC themselves. Being too busy or forgetting is not a reasonable excuse. Your accountant being slow is sometimes accepted if you can show you gave them information in good time.
How do I know if HMRC has my correct bank details?
If you have previously received a refund to your bank account, HMRC has your details. If you have only ever paid them, they probably do not. You do not need to give HMRC your bank details to pay, but you do need them to receive refunds.
Tools to Help You Plan
Use our free Director Salary Calculator to work out your optimal salary and dividend mix for the current tax year.
If you are concerned about the dividend tax increase coming in April 2026, our guide explains how it affects your take-home pay and what you can do about it.
For tax-efficient profit extraction, read our guide on pension contributions for directors.
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