The SA302 tax calculation is HMRC’s official summary of your income and the tax you owe for a given year, and once your Self Assessment return has been filed you can view and print it from your online HMRC account for any of the last four years.1GOV.UK. Get Your SA302 Tax Calculation Most people ask for one when a mortgage lender wants proof of self-employed income, and the document is almost always requested alongside a second one called the Tax Year Overview.
What the SA302 Shows
The SA302 pulls the figures from your filed return into a single calculation: total income from every source you declared, the allowances and reliefs you claimed, the workings HMRC used, and the total tax due for the year.2GOV.UK. Understand Your Self Assessment Tax Bill – Tax Calculation SA302 Each income line ties back to a specific section of your return, so any figure on the calculation can be traced to what you reported. If you have self-employment income, the National Insurance contributions due on that income appear on the calculation as well.
What the SA302 does not show matters just as much. It leaves out payments on account you’ve already made toward next year’s bill, anything paid into a Budget Payment Plan, and other outstanding balances such as unpaid penalties.2GOV.UK. Understand Your Self Assessment Tax Bill – Tax Calculation SA302 Those sit on the Tax Year Overview, which is a separate document. Treating the two as interchangeable is the most common source of trouble in a mortgage application.
How to Get Your SA302 Online
The quickest route is your HMRC online account. Sign in with your Government Gateway credentials, go to Self Assessment, then choose “More details about your Self Assessment returns and payments.”1GOV.UK. Get Your SA302 Tax Calculation From the “At a glance” page, select “Tax return options,” pick the tax year you need, and the calculation is there to view, save, or print. The last four years of returns are available this way.
HMRC is gradually rolling out GOV.UK One Login in place of Government Gateway, but if you already have a Government Gateway account you should continue to sign in as normal until HMRC prompts you to switch.
If you filed through commercial software rather than the HMRC portal, the calculation will not appear in the online account. You need to print it from within the software itself, where it may be labelled a “tax computation.”1GOV.UK. Get Your SA302 Tax Calculation The figures are the same, and lenders signed up to HMRC’s verification agreement accept the software version.
Getting a Paper Copy by Post
If you filed a paper return, HMRC posts the calculation to you automatically.2GOV.UK. Understand Your Self Assessment Tax Bill – Tax Calculation SA302 For a duplicate, or if you can’t use the online account, call the Self Assessment helpline on 0300 200 3310, open Monday to Friday, 8am to 6pm, and closed on bank holidays.3GOV.UK. Self Assessment General Enquiries The document goes to the address HMRC holds on file, so check that address is current before you call.
Delivery usually takes ten to fifteen business days, and longer around the 31 January filing peak. If a mortgage deadline is close, use the online route. If post is your only option, give yourself at least three weeks. HMRC no longer faxes SA302s, so any lender still asking for one by fax is working from outdated guidance.
Using the SA302 With the Tax Year Overview
Mortgage lenders usually ask self-employed applicants and company directors for both documents, typically covering the last two years.4GOV.UK. List of Mortgage Providers and Lenders Who Accept a SA302 Tax Calculation and a Tax Year Overview The SA302 evidences what you earned; the Tax Year Overview evidences what you actually paid. Together they form a matched pair.
The Tax Year Overview is effectively a statement of account. It shows what you owed, what you’ve paid, and any balance still outstanding, and it includes payments on account, which are the advance instalments due on 31 January and 31 July toward next year’s bill.2GOV.UK. Understand Your Self Assessment Tax Bill – Tax Calculation SA3025GOV.UK. Self Assessment Tax Returns – Deadlines You print it from the same area of your online account as the SA302.1GOV.UK. Get Your SA302 Tax Calculation
If the figures on the two documents don’t line up, a lender will notice. A mismatch can mean tax is still outstanding, a payment has been allocated to the wrong year, or the return was amended after the SA302 was first generated. Fixing any discrepancy before you submit anything is far quicker than trying to explain it to underwriters afterwards.
Not every lender has signed up to HMRC’s arrangement to accept self-printed and software-produced copies, so confirm with your specific lender what they will accept before you send documents over.
Deadlines That Affect When Your SA302 Is Available
The calculation only exists once HMRC has processed your return, so filing dates dictate when you can get one. For the 2024-25 tax year, the paper filing deadline is 31 October 2025 and the online filing deadline is 31 January 2026, with the tax itself also due by 31 January 2026.5GOV.UK. Self Assessment Tax Returns – Deadlines If you want HMRC to collect what you owe through your PAYE tax code, you need to file by 30 December 2025.
Filing earlier in the year has a straightforward benefit: the SA302 becomes available sooner. If you know a mortgage application is coming up in spring, filing in April or May puts the document in your hands months ahead of time. Waiting until January offers nothing unless your figures aren’t ready.
Fixing a Mistake After Filing
If you notice an error on a filed return, you can amend it online. Wait 72 hours after your original submission, sign in, and go back to “Tax return options.” Pick the year, make your corrections, and file again.6GOV.UK. Self Assessment Tax Returns – If You Need to Change Your Return An updated SA302 is generated with the revised figures.
The amendment window runs for 12 months from the 31 January deadline following the end of the tax year. For a 2024-25 return, that gives you until 31 January 2027.6GOV.UK. Self Assessment Tax Returns – If You Need to Change Your Return If the window has already closed and you’ve overpaid, you can still claim overpayment relief within four years of the end of the relevant tax year.7GOV.UK. Self Assessment Claims Manual – SACM12155 – Overpayment Relief: Time Limits for Making a Claim
Keep in mind that the SA302 only reflects what you reported. It isn’t a sign-off from HMRC that your figures are correct, and it won’t shield you if an enquiry later finds errors. Records that support every line on your return are the real protection.