UK Personal Tax Timeline
January 2026
31 January
- Deadline for online Self Assessment tax returns for the 2024/25 tax year (by midnight)
- Balancing payment due for the 2024/25 tax year
- First Payment on Account due for the 2025/26 tax year.
Late filing penalties and interest apply immediately after this date.
February 2026
Penalties & Enforcement Begin
1 February
- £100 late filing penalty applies if your Self Assessment return was not submitted by 31 January
- Interest continues to accrue on any unpaid tax
- Check account balances are up to date and payments allocated
March 2026
Penalties Escalate, Review & Optimise
Around 2 March 2026
- 5% late payment penalty charged on any 2024/25 tax still unpaid 30 days after the 31 January deadline
- Further interest continues to accrue on outstanding balances
- Opportunity to submit a late Self Assessment return and limit further penalties
- Time to correct or amend recently filed returns before the new tax year begins
- Review whether Payments on Account are accurate and consider a claim to reduce them if your income has fallen
- Ideal month for tax planning actions ahead of the 5 April tax year end (pension contributions, capital gains planning, Gift Aid)
- Sensible point to speak to a tax adviser if you are unsure about liabilities or next steps
- Check tax code for 2026/27 to correct any errors
- Register for MTD to ensure compliance from April 2026
April 2026
New Tax Year & Making Tax Digital Changes
6 April: 2026/27 UK Tax Year Begins
- New allowances become available (Personal Allowance, ISA allowance, CGT exemption, dividend allowance)
- You can file your Self Assessment return from this date
Making Tax Digital (Income Tax) Begins For:
- Self‑employed individuals and landlords with qualifying income over £50,000
- Requirement to keep digital records and submit quarterly updates to HMRC
Deadline for claiming tax reliefs for 2021/22
Filing early helps you understand your tax liability well ahead of the January deadline, even though payment is not due yet.
By 31 May
- Employers must issue P60s
- Useful for checking income and tax paid during the tax year
- 1st May daily penalties for 2024/25 tax returns not yet filed
- Consider collating tax information if a tax charge is expected on pension savings and election is required for the scheme to pay
June 2026
Benefits, Allowances & Planning Window
- Review P60 information and ensure income and tax deducted look correct
- Common month to receive details of benefits-in-kind (company cars, medical insurance, etc.) ahead of P11D reporting
- Useful planning window for:
- Pension contributions
- ISA subscriptions
- Capital gains planning
- Good time to address errors early before HMRC P11D deadlines in July
July 2026
31 July
- Second Payment on Account due for the 2025/26 tax year
August 2026
Quiet Month, But Useful Checkpoint
- No formal HMRC personal tax deadlines
- Good time to:
- Review tax payments made in January and July
- Check HMRC statements for errors or unexpected balances
- Ensure records are being kept up to date (especially for landlords and the self-employed)
- Useful month to resolve issues before autumn deadlines approach
- 2nd late payment penalty of 5% if 2024/25 balance is still outstanding
- Additional late filing penalty if 2024/25 tax return is still outstanding (min £300)
- 5 August MTD 1st quarterly return due for 2026/27
September 2026
Preparation Month
- No formal filing deadlines, but an important preparation window
- Ideal time to:
- Gather records for Self Assessment
- Estimate tax liability ahead of January
- Check whether you need to register for Self Assessment by 5 October
- Good point to speak to a tax adviser if circumstances have changed (new income, property sales, self-employment)
5 October
- Deadline to register for Self Assessment for the 2025/26 tax year (if required)
31 October
- 31 October: Deadline for paper Self Assessment tax returns for the 2025/26 tax year**
November 2026
Final Preparation Window
- No formal HMRC deadlines, but an important month for final preparation
- Ideal time to:
- Complete online Self Assessment tax returns ahead of the January rush
- Finalise income and expense records
- Calculate likely tax liabilities and plan cash flow
- Useful period to resolve queries with HMRC or your adviser before December cut-offs
- 5 November MTD 2nd quarterly return due for 2026/27
December 2026
30 December
- Deadline for submitting an online tax return for the 2025/26 tax year if you want any tax owed (under £3,000) to be collected through your 2027/28 PAYE tax code
- Final opportunity for last-minute tax planning before the January deadline
Dates shown are correct for a page published in 2026 and cover current and upcoming deadlines for the 2025/26 and 2026/27 tax years. Deadlines may change in future tax years.
Frequently Asked Questions
Core Filing & Deadline Questions
The deadline for submitting your Self Assessment tax return online is 31 January following the end of the tax year. The deadline for paper tax returns is 31 October.
HMRC sets an earlier deadline for paper returns (31 October) because manual processing takes longer. If you miss the paper deadline, you can still file online by 31 January.
Yes – you can file your return anytime after 6 April (start of the new tax year), even though payment isn’t due until 31 January.
Missing a deadline typically triggers an automatic £100 penalty, with further penalties and interest applied if the return remains late.
Payments & Costs
Any tax you owe must be paid by 31 January along with your online return. If your liability was over £1,000, you may also have to make Payments on Account (31 January and 31 July).
If you owe more than £1,000 after filing, HMRC usually requires two advance payments toward next year’s tax – one on 31 January and one on 31 July.
- If you don’t pay on time, a 5% penalty may be charged on tax still unpaid 30 days after the 31 January deadline, plus interest until payment is made.
Registration & Other Filing Issues
You must register with HMRC for Self Assessment by 5 October after the end of the relevant tax year if you have untaxed income or capital gains.
If you register late, HMRC may issue a different filing deadline (often 3 months after registration) – but late registration can also trigger a penalty.
From 6 April 2026, qualifying self-employed individuals and landlords with income over £50,000 must use MTD for Income Tax – keeping digital records and submitting quarterly updates to HMRC, instead of only an annual return.
MTD applies to self-employed individuals and landlords with qualifying income above the threshold. HMRC notifies those affected, and they must sign up before it becomes mandatory.
You will need digital bookkeeping software or tools that link to HMRC, keep digital records, and send quarterly updates, plus a final submission by 31 January.
Generally, you need to file if you’re self-employed, a landlord, have untaxed income, or have certain investment gains. HMRC guidance and tools as well as the team at Ward Goodman can help determine this.
Yes – in most cases, you can amend a return within a set period after submission if you find errors. (HMRC guidance explains how and when amendments are allowed.)
Relevant records include income, expenses, P60/P45, rental income details, capital gains, and any pension or donation information. Quarterly records will be needed under MTD.
