The 2024/25 UK tax year dates are 6 April 2024 to 5 April 2025. Income earned inside that window is assessed together, allowances that reset annually expire at midnight on 5 April 2025, and the main filing and payment deadline for the year is 31 January 2026 for online Self Assessment returns.
Key Dates at a Glance
- 6 April 2024: 2024/25 tax year begins.
- 31 January 2025: balancing payment for 2023/24 and first payment on account for 2024/25.
- 5 April 2025: 2024/25 tax year ends. ISA, capital gains, and dividend allowances expire.
- 31 July 2025: second payment on account for 2024/25.
- 5 October 2025: deadline to register for Self Assessment if you need to file for 2024/25 and haven’t filed before.
- 31 October 2025: paper Self Assessment return deadline (11:59pm).
- 31 January 2026: online Self Assessment return deadline, balancing payment for 2024/25, and first payment on account for 2025/26 (all 11:59pm).
When the Tax Year Starts and Ends
The tax year opens on 6 April 2024 and closes on 5 April 2025. The Income Tax Act 2007 sets those boundaries, and any income landing even a day outside the window belongs to a different tax year. Employment earnings, savings interest, dividends, rental income, and capital gains are all measured against this period when HMRC calculates what you owe.
Corporation Tax works to its own timetable: a company’s accounting period doesn’t have to align with 6 April, so its deadlines run from its own year-end rather than from the personal tax year.1GOV.UK. Pay Your Corporation Tax Bill
Self Assessment Filing Deadlines for 2024/25
If you need to file a Self Assessment return for the 2024/25 year, three cut-offs matter.
You must tell HMRC you need to file by 5 October 2025 if you haven’t sent a return before or didn’t need to file for the previous year. That registration triggers your Unique Taxpayer Reference number, which you’ll use for every subsequent filing.2GOV.UK. Self Assessment Tax Returns – Deadlines
Paper returns must reach HMRC by 11:59pm on 31 October 2025. Online returns have a final deadline of 11:59pm on 31 January 2026.2GOV.UK. Self Assessment Tax Returns – Deadlines
The paper cut-off catches people out. If you had planned to file on paper but miss 31 October, switching to online submission gives you three extra months.
Families where the higher earner has adjusted net income above £60,000 need to check whether the High Income Child Benefit Charge applies. If it does, and you crossed that threshold during 2024/25, you’ll need to register for Self Assessment and report the charge by 31 January 2026 even if you have no other reason to file.3House of Commons Library. The High Income Child Benefit Charge
Payments on Account
Tax on 2024/25 income is collected across three dates rather than one lump sum. On 31 January 2025 you paid any balance owed on 2023/24, plus a first payment on account for 2024/25 equal to half of that previous year’s tax bill. On 31 July 2025 a second payment on account covers the other half.4GOV.UK. Understand Your Self Assessment Tax Bill – Payments on Account
The final balancing payment for 2024/25 falls on 31 January 2026. HMRC compares what you actually owe against the two estimated payments you’ve already made; if the real bill is higher, you pay the difference, and if it’s lower the overpayment is refunded or credited to the following year. The same 31 January 2026 date is when the first payment on account for 2025/26 becomes due.4GOV.UK. Understand Your Self Assessment Tax Bill – Payments on Account
If your income has dropped compared with the previous year, you can apply to reduce your payments on account online or by post. The claim must be made by 31 January after the end of the tax year. Estimate conservatively: if you reduce the payments and then owe more than expected, HMRC will charge interest on the shortfall.5GOV.UK. Claim to Reduce Payments on Account
Allowances That Expire on 5 April 2025
Several tax-free allowances reset to zero the moment the new tax year opens. Most cannot be carried forward, so anything unused simply disappears.
ISA Allowance
You can save up to £20,000 across all your Individual Savings Accounts in 2024/25. Any unused portion is permanently lost on 6 April. You cannot carry it forward, backdate contributions, or combine it with next year’s allowance.6GOV.UK. Individual Savings Accounts – How ISAs Work
Capital Gains Tax Annual Exempt Amount
The tax-free allowance for capital gains is £3,000 per individual for 2024/25, down sharply from £12,300 two years earlier. Gains above that are taxable at rates depending on your income tax band and the asset sold. Unused CGT exemption cannot be carried forward.7HM Revenue & Customs. Capital Gains Tax Rates and Allowances
Dividend Allowance
The tax-free dividend allowance for 2024/25 is £500. Dividend income above that is taxed at 8.75%, 33.75%, or 39.35% depending on which income tax band applies.8GOV.UK. Tax on Dividends
Pension Annual Allowance
The pension annual allowance for 2024/25 is £60,000 for most earners, covering your own contributions, employer contributions, and tax relief added by HMRC.9GOV.UK. Pension Schemes Rates Unlike the others in this section, unused pension allowance can be carried forward from up to three previous tax years.
Inheritance Tax Gift Exemption
Each individual can give away £3,000 per tax year free of inheritance tax. If you didn’t use your full 2023/24 exemption, the unused balance can be carried into 2024/25, but only for that one year. Once 5 April 2025 passes, any unused 2024/25 exemption carries forward to 2025/26 under the same one-year rule, and the 2023/24 carryover is gone.10GOV.UK. How Inheritance Tax Works – Gifts
Personal Allowance and Income Tax Bands
The personal allowance stays frozen at £12,570 for 2024/25. Above that, the basic rate of 20% applies to taxable income up to £50,270, the higher rate of 40% from £50,271 to £125,140, and the additional rate of 45% above £125,140. If your adjusted net income exceeds £100,000, the personal allowance tapers by £1 for every £2 above that level and disappears entirely at £125,140.11GOV.UK. Income Tax Rates and Personal Allowances
The 60-Day Deadline for Property Gains
Selling a UK residential property at a gain during 2024/25 triggers a reporting deadline that sits outside the normal Self Assessment timetable. The gain must be reported and any tax paid within 60 days of completion. This applies to second homes, buy-to-let properties, and any residential property not fully covered by private residence relief.12GOV.UK. Report and Pay Your Capital Gains Tax – Property Sold on or After 6 April 2020
The 60 days run from completion, not from exchange. Interest and penalties apply for late reporting, and you still need to include the gain on your Self Assessment return for the year.
What Happens if You Miss a Deadline
The penalty structure for Self Assessment escalates quickly. Missing the filing deadline by a single day brings an automatic £100 fine, whether or not you owe any tax. After three months, daily penalties of £10 begin accumulating for up to 90 days, adding a maximum of £900. After six months, HMRC adds 5% of the tax due or £300, whichever is greater. At twelve months, another 5% or £300 is applied on top.13GOV.UK. Self Assessment Tax Returns – Penalties
Late payment carries separate consequences. HMRC charges a 5% surcharge on tax unpaid after 30 days, another 5% after six months, and a further 5% after twelve months.13GOV.UK. Self Assessment Tax Returns – Penalties
Interest runs on top of penalties. For any late payment relating to 2024/25, the rate from 6 April 2025 onward is the Bank of England base rate plus 4%, up from the previous formula of base rate plus 2.5%.14HM Revenue & Customs. HMRC Interest Rates for Late and Early Payments
HMRC will waive penalties if you can show a reasonable excuse for filing late. Recognised excuses include serious illness, the death of a partner or close relative shortly before the deadline, a fire or flood that destroyed records, unexpected computer failures during online submission, and problems with HMRC’s own online services. Not having enough money, finding the online system confusing, or not receiving a reminder will not qualify.15GOV.UK. Disagree With a Tax Decision or Penalty – Reasonable Excuses You must also file as soon as the obstacle is resolved: a hospital stay in December will not excuse a return submitted the following June if you were well again in January.