Documents you need for your 2025/26 Self Assessment return

The 2025/26 return: dates and what it covers

The 2025/26 tax year ran from 6 April 2025 to 5 April 2026. The return reports income and gains for that year only. These are the dates on GOV.UK:

• 31 October 2026: deadline for a paper return (HMRC must receive it)
• 30 December 2026: last day to submit your online return if you want to pay your Self Assessment bill through your tax code
• 31 January 2027: deadline for the online return and for paying the tax you owe
• 5 October 2026: the date to tell HMRC you need a return if you had not sent one before. If you register after that, HMRC sets a deadline 3 months from the date on its letter or email, but the tax is still due by 31 January 2027

You can file any time from 6 April 2026. Start with the documents below and tick them off. Our downloadable checklist template follows the same order.

Personal details and login

• Your 10-digit Unique Taxpayer Reference (UTR)
• Your Government Gateway user ID and password
• Your National Insurance number
• Bank account details for any refund
• If an agent files for you, your authority for them to act (the agent will tell you how HMRC wants it given)

If you have lost your UTR, look in your HMRC online account or on earlier Self Assessment letters. Recover a lost Government Gateway login early, not in the last week of January.

Employment

• P60: total pay and tax for the year, from each employer you were paid by on 5 April 2026
• P45: if you left a job during the year, for pay and tax up to the leaving date
• P11D: taxable benefits in kind such as a company car or private medical cover
• Final payslip for each job as a cross-check
• Details of any employment expenses you intend to claim, with receipts
• Redundancy or termination payment letters, if you had one

Self-employment (sole trader or partnership)

• Total turnover for the year, with invoices or sales records and platform payout statements
• Business bank statements for 6 April 2025 to 5 April 2026
• Receipts and records for every expense you claim, with the business share of mixed-use costs
• Mileage log if you claim vehicle costs, or the figures for simplified expenses
• Purchase dates and costs of equipment and vehicles bought, for capital allowances
• Details of any trading losses brought forward
• CIS statements from contractors, if you are a subcontractor
• Partnership statement, if you are a partner

Income from the £1,000 trading allowance still needs records of that income. If you sell online or earn from content, platforms report to HMRC from 1 January 2024: ask for or download your platform summary and match it to your own records. See our guide to the trading allowance.

Property income

• Rent received, by property, from agent statements or your own records
• Agent and management fees, insurance, ground rent and service charges
• Repairs and maintenance receipts, kept separate from improvements
• Mortgage interest statements for the year, for the finance cost relief calculation
• Details of any properties bought or sold
• Your share of income and costs for jointly owned property

GOV.UK gives a £1,000 property allowance. Gross property income over £2,500 means you must register for Self Assessment.

Savings interest

• Interest certificates or year-end statements from each bank, building society or savings provider
• Interest on joint accounts: HMRC splits it equally between holders unless told otherwise
• Foreign savings interest, with the tax deducted

Banks report interest to HMRC after 5 April. Interest in ISAs is not usually taxable. See GOV.UK: tax on savings interest.

Dividends

• Dividend vouchers or statements from each company, including your own
• Dividend records from share platforms and funds

The dividend allowance was £500 for 2025/26, per HMRC's rates table. Dividend income above your unused Personal Allowance and the dividend allowance has to be reported.

Pensions

• State Pension: your pension statement or payment details. The State Pension is taxable
• Private and workplace pension income and P60 or P45 from the provider
• Pension contribution statements for personal pensions, including contributions paid by someone else

If you pay Income Tax above 20% and contribute to a relief-at-source scheme, you can claim the extra relief on the return. See GOV.UK: pension tax relief.

Capital gains

• Description of each asset you sold or gave away in 2025/26
• Date and price of purchase, and date and proceeds of sale
• Costs of buying, selling and improving the asset
• Share and crypto transaction histories, with pooled cost records
• Contract and completion statement for any property sold
• Losses carried forward from earlier years

The Capital Gains Tax annual exempt amount for 2025/26 is £3,000, per HMRC. You must send a return if you had to pay Capital Gains Tax.

Gift Aid and charity

• A record of each Gift Aid donation made in the tax year, with the charity name and amount
• Any donations made after 5 April 2026 that you want to carry back, if you pay the higher rate

Higher-rate taxpayers claim back the difference on the return. See GOV.UK: Gift Aid.

Child Benefit and the High Income Child Benefit Charge

• Child Benefit amounts received in the year, from your statement or award notice
• Your partner's adjusted net income, if you are not sure who has the higher income
• Any opt-out date, if you stopped payments

For tax years from 2024/25, the charge applies where adjusted net income is over £60,000. You repay 1% of the Child Benefit for every £200 over £60,000, and all of it at £80,000 or more. If you and your partner are both over the threshold, the higher earner pays. If you must send a return for another reason, you pay the charge through Self Assessment. Source: GOV.UK: High Income Child Benefit Charge.

Student and postgraduate loans

• Your repayment plan type (Plan 1, 2, 4 or 5, and any Postgraduate Loan)
• Repayments already taken through payroll, from your P60 or payslips

HMRC works out repayments for the whole year from the return if you are self-employed or file for another reason, and deducts what payroll has already taken. See GOV.UK: student loan repayments.

Foreign income

• Statements for overseas wages, pensions, rent, dividends and interest, in the original currency
• Evidence of tax paid abroad, such as certificates or tax returns
• Details of your UK residence position for the year

UK residents normally pay tax on foreign income and report it in a Self Assessment return. Relief may be available if the income is taxed in more than one country. See GOV.UK: tax on foreign income.

Other reliefs and allowances

• Marriage Allowance details, if you gave or received it
• Married Couple's Allowance details, if you qualify
• Blind Person's Allowance registration, if it applies
• Details of any losses to claim

If Making Tax Digital for Income Tax starts for you in April 2026

Making Tax Digital for Income Tax applies from 6 April 2026 to sole traders and landlords registered for Self Assessment with qualifying income over £50,000 in 2024/25. Qualifying income is self-employment and property income before expenses. Employment, dividends and pensions are not counted. The next thresholds are £30,000 from 6 April 2027 and £20,000 from 6 April 2028. See GOV.UK.

You still send a Self Assessment return for 2025/26 by 31 January 2027, before you start using MTD. For the new system, have these ready:

• Your 2024/25 return figures, to confirm qualifying income
• Any HMRC letter or sign-up notice. From September 2026 HMRC signs up people whose records show over £50,000 in 2024/25
• Compatible software chosen, and authorised with HMRC. HMRC does not provide software
• A digital record of income and expenses from 6 April 2026, kept in the software
• Your agent's details, if one will send the quarterly updates

See our guides to Making Tax Digital for sole traders and landlords.

How long to keep records

If you are self-employed, GOV.UK says to keep your records for at least 5 years after the 31 January submission deadline of the relevant tax year. For the 2025/26 return, filed by 31 January 2027, that means at least until the end of January 2032. Keeping the same documents for the same period for other income types costs nothing and makes an enquiry easier to answer. If a record is lost, tell HMRC when you file whether the figure is estimated or provisional. See GOV.UK: how long to keep your records.

Summary

• The 2025/26 return is due online by 31 January 2027, with payment due the same day
• Collect documents by income type: employment, self-employment, property, savings, dividends, pensions, gains
• Check Child Benefit, Gift Aid, student loan and pension relief items that change the bill
• Check whether Making Tax Digital applies to you from April 2026