SA302 Tax Calculation: Proof of Income Explained

An SA302 tax calculation is HMRC's summary of the income and tax on your Self Assessment return for one tax year, and it is the document most mortgage lenders ask self-employed people for as proof of income. You can usually download it, together with a Tax Year Overview, from your HMRC online account once your return has been filed. This guide explains what each document shows, how to get them, and how to avoid the delays that can hold up a mortgage or rental application.

Key takeaways

• The SA302 shows your income and tax for one year, based on your filed return.
• Lenders normally want it with the matching Tax Year Overview.
• You can only get it after the return for that year has been filed.
• Many lenders ask for two years, so file the latest year early if you plan to apply.
• The figures come from your return, so they are only as good as your records.

What is an SA302?

SA302 is the name HMRC uses for the tax calculation produced from your Self Assessment return. It sets out your income from self-employment, employment, property, savings and dividends, the allowances given and the Income Tax and National Insurance due for that tax year. GOV.UK has a page on how to get your SA302 tax calculation, including what to do if you filed with commercial software.

Because self-employed people do not receive payslips or a P60 for their business income, the SA302 is often the clearest independent evidence of what they earn. Directors who take dividends are in a similar position, as dividends only show up on the tax return.

SA302 and other proof of income compared

Step-by-step: downloading your SA302 and Tax Year Overview

1. Make sure the return is filed. No return means no calculation. The 2025/26 online return is due by 31 January 2027.
2. Allow a short time after filing. The calculation may not appear in your account immediately, so do not leave it until the day before a lender deadline.
3. Sign in to your HMRC online account using your Government Gateway or other sign-in details.
4. Open your Self Assessment returns and choose the tax year you need.
5. Print or save the tax calculation and the Tax Year Overview for each year the lender wants.
6. Check the figures match your return and the year is correct before sending them.
7. Ask for help if you cannot print them. GOV.UK explains how to request them from HMRC if the online route does not work for you.

Timing: why filing early helps

Lenders generally want the most recent tax year. If you plan to apply for a mortgage in early 2027, filing your 2025/26 return now rather than in late January means the latest calculation is available sooner, and any questions about your figures can be dealt with before the application. Our 31 January countdown plan and documents checklist will help you get there. If you are not yet registered or are behind, GOV.UK's Self Assessment tax returns guidance is the starting point.

Worked example (illustrative example)

Illustrative example only, not a real client. Priya has been a self-employed physiotherapist for three years and wants to buy a flat in spring 2027. Her broker asks for SA302s and Tax Year Overviews for the last two years. Priya filed her 2024/25 return in January 2026, but has not started 2025/26.

In October 2026 she gathers her records, files the 2025/26 return in November, and downloads both years' calculations and overviews a few days later. Her 2025/26 profit is higher than 2024/25, so the lender has up-to-date evidence of the increase. Had she waited until late January, her application would have been based on older, lower figures or delayed while the new return was processed.

Common mistakes

• Sending the calculation without the overview. Most lenders want both for each year.
• Sending the wrong year. Tax years run 6 April to 5 April, so check the dates on each page.
• Leaving tax unpaid. The overview shows any amount outstanding, which a lender will notice. See payments on account for how the bill is built up.
• Inflating income to borrow more. The figures must reflect your true records. Any change must be a genuine correction, made by amending the return.
• Missing returns. A gap in filing history can delay an application; our catch-up guide explains how to put it right.

How we can help

We are a London-based specialist accounting practice with fixed fees. Our personal tax service starts from £180 per year, and we can file your return early, provide the tax calculation from our filing software and help you download your HMRC documents ready for a lender. See our personal tax service, check our pricing, or contact us.