United Kingdom: what to claim, what to file, in what order
Tax year 6 April 2025 to 5 April 2026 (2025/26). Everything on this page is specific to United Kingdom, so nothing here is a general rule that quietly does not apply to you.
Figures as published by HM Revenue and Customs for 2025/26. Check gov.uk before you file, and remember Scotland sets its own income tax bands.
Moves that cut this year's bill
These are the United Kingdom moves you can make yourself, with no adviser and no structure to set up. They only count if the money moves before 5 April.
Pay more into a pension
Money you put in comes out of your taxable pay, so the taxman gives part of it back.
Relief at your top rate, so 40 pence back in every pound at the higher rate, and 60 pence in the band above 100,000.
Cost: £0 to £0 to set up, £0 to £150 a year.
Dan, 44, project manager in Leeds on £68,000
Puts £6,000 into his workplace pension by salary sacrifice. That £6,000 all sat in the 40% band.
£2,400 less income tax and £120 less National Insurance. £6,000 in his pension has cost him £3,480 of take home pay.
Rule behind it: Annual allowance 60,000 for 2025/26, relief at your marginal rate
Fill your ISA first
A wrapper around savings and investments. Nothing inside it is ever taxed again.
No tax on interest, dividends or gains, and nothing to report on a tax return.
Cost: £0 to £0 to set up, £0 to £100 a year.
Margaret, 68, Devon, £90,000 from her sister's estate
£20,000 into an ISA now, £20,000 again on 6 April, the rest in premium bonds and gilts meanwhile.
At 4.5% interest, £40,000 outside an ISA would show £1,800 of taxable interest. Inside, nothing is taxed and nothing is reported.
Rule behind it: ISA allowance 20,000 per person per tax year
What you can deduct or claim in United Kingdom
Pension contributions
Relief at your highest rate, so £1,000 in costs a higher rate taxpayer £600.
Employed and self-employed
Work expenses you paid yourself
Uniform and tool allowances, professional subscriptions, mileage at 45p for the first 10,000 miles.
Employees
Working from home
£6 a week without receipts where your employer requires home working.
Employees
Business costs
Anything wholly for the trade: stock, tools, insurance, software, accountancy, plus a share of home costs.
Self-employed
Mortgage interest on lettings
A 20% tax reducer rather than a deduction from rent.
Landlords
Gift Aid donations
Extends your basic rate band, so higher rate taxpayers claim the difference back.
Everyone
Capital allowances
Full expensing and the £1m annual investment allowance on qualifying equipment.
Businesses
The filing steps, in order
- 1
Gather what came in
P60 and P45 from work, P11D for benefits, bank and dividend statements, rent records, and paperwork for anything you sold.
As soon as the tax year ends on 5 April
- 2
Register if you need to send a return
New to Self Assessment, or newly self employed, a landlord, or over the high income child benefit level? Register for a Unique Taxpayer Reference first, it takes a couple of weeks to arrive.
5 October after the tax year ends
- 3
Make your before year end moves
Pension top ups, ISA subscriptions, gift aid, transferring assets to a spouse and using your capital gains allowance only count if they happen inside the tax year.
5 April
- 4
Claim reliefs and expenses
Work expenses, professional fees, marriage allowance, pension relief above basic rate, rent a room and the property or trading allowance all go on the return or a separate claim.
With the return, and up to four years back for most claims
- 5
File the return
Online through your HMRC account, using the supplementary pages for property, self employment or gains.
31 January after the tax year ends
- 6
Pay, including payments on account
Pay the balance for last year plus the first payment on account for this year. A second payment on account follows in July.
31 January, then 31 July
- 7
Keep the records
Five years after the filing deadline if you are self employed or a landlord, otherwise two years.
Ongoing
Forms to file with HMRC
| Form | What it does | When | Who needs it |
|---|---|---|---|
| Self Assessment SA100 | The main tax return | Online by 31 January after the tax year ends | Self-employed, landlords, high earners, anyone with untaxed income |
| SA105 | Property pages for rental income | With your return | Landlords |
| SA103 | Self-employment pages | With your return | Sole traders |
| SA108 | Capital gains pages | With your return | Anyone selling assets |
| P87 | Claim work expenses without a full return | Any time, backdated four years | Employees |
| Marriage Allowance claim | Transfer £1,260 of allowance to a spouse | Any time, backdated four years | Couples where one earns under the allowance |
| CGT on UK property return | Report and pay gains on residential property | Within 60 days of completion | Sellers of second homes and lettings |
| IHT400 | Estate accounts after a death | Within 12 months, tax due at 6 months | Executors |
| CT600 | Company tax return | 12 months after the accounting period, tax due at 9 months and a day | Limited companies |
| SL1 / Student Loan Start Notice | Tells your employer which plan to use | When you start a job with a loan | Employees with student loans |
| High Income Child Benefit Charge | Declared in Self Assessment | By 31 January after the tax year | Highest earner over £60,000 with child benefit |
| SDLT return | Pay Stamp Duty Land Tax on most property purchases | Within 14 days of completion | Buyers in England and Northern Ireland |
| LBTT return | Pay Land and Buildings Transaction Tax in Scotland | Within 30 days of the effective date | Buyers in Scotland |
| LTT return | Pay Land Transaction Tax in Wales | Within 30 days of completion | Buyers in Wales |
Not covered on this page
- Complex trust, estate and partnership tax calculations
- Pension annual allowance tapering for very high earners
- Venture Capital Scheme eligibility and carry-back claims
- Tax year: 2025/26. Your year ends 5 April.