SA302 tax calculations and tax year overviews

An SA302 is HMRC’s tax calculation for one Self Assessment year, and the tax year overview shows how much of that tax has been paid. Mortgage lenders usually ask for both as evidence of self employed or other non salary income. You can print them yourself from your HMRC online account 72 hours after filing, for up to 4 years, and if your accountant files using commercial software the calculation comes from that software while the overview still comes from HMRC’s online account.

What are the SA302 and the tax year overview?

When you submit a Self Assessment return you get a statement (your bill) and a tax calculation, which HMRC also calls an SA302 or a tax computation. GOV.UK says the calculation shows:

• your total income on which tax is due;
• any allowances and reliefs you have;
• the total amount you owe for the tax year;
• how HMRC worked out that amount.

It does not include payments on account you have made, payments into a Budget Payment Plan, or other amounts outstanding such as unpaid tax or penalties. That is why lenders also ask for the tax year overview. HMRC’s guidance for lenders, published through the Chartered Institute of Taxation, describes it as showing the total tax due and how much the customer has paid directly to HMRC. The same guidance warns lenders not to confuse either document with the Annual Tax Summary, which shows how tax is spent.

Why do mortgage lenders want them?

The FCA’s mortgage rules require a lender assessing affordability to obtain evidence of the income the customer has declared. The evidence must be adequate for each element of income and subject to anti fraud controls. The lender must not accept self certification, and the evidence must be independent of the customer (MCOB 11.6.8R). The guidance at MCOB 11.6.9G explains that evidence can be independent even when the customer supplies it, giving tax returns as an example, and that for self employed customers a lender may also consider projections in a credible business plan.

HMRC documents meet that need because they show income the customer has declared to HMRC and the tax charged on it. HMRC’s guidance for lenders makes some points worth knowing:

• the figures are correct at the time of printing, but the customer can still amend the return, usually up to 12 months after the 31 January filing deadline;
• lenders should not necessarily expect the tax to have been paid before 31 January, because that is when the balance is due;
• HMRC call centre staff cannot talk to lenders directly; lenders signed up to the Mortgage Verification Scheme can ask HMRC to verify documents through that service;
• lenders should consider other evidence about income where necessary.

How do you get them yourself?

If you filed using HMRC’s online services, sign in to your HMRC online account, go to “Self Assessment” and then “More details about your Self Assessment returns and payments”. From there you can print the tax calculation for each of the last 4 years and a tax year overview for any year. You cannot print them until 72 hours after you sent the return, so if a lender needs them urgently, file early. If you sent a paper return, HMRC posts the calculation to you after processing it. You can contact HMRC if you have problems getting the documents, for example if you need a copy on HMRC headed paper.

Check that your lender accepts documents you have printed yourself. HMRC publishes a list of lenders that have agreed to accept the self printed tax calculation and tax year overview. It includes most large banks and building societies, but it was last updated on 8 June 2020, so confirm with the lender or broker before relying on it.

What if your accountant uses commercial software?

Many accountants file using commercial software. In that case GOV.UK says you must print the tax calculation from that software, which may call it something else such as a “tax computation”. You can still print the tax year overview from your own HMRC online account. The CIOT guidance confirms that lenders following the agreed process ask for both documents together: the calculation from the software and the overview from the online account.

In practice, an agent will:

1. produce the tax computation from the filing software for each year the lender wants;
2. ask the client to print the tax year overview for the same years from their personal account, or explain how to do so;
3. check that the tax due on the overview agrees with the computation;
4. send them to the client to pass to the lender or broker.

Your access to HMRC services as an agent depends on how the client has authorised you; see our guide to the agent services account.

Should an accountant give a financial reference as well?

Lenders sometimes ask the accountant for a reference letter in addition to, or instead of, the HMRC documents. The CIOT and ATT guidance on mortgage references says that giving one can create a duty of care to the lender, and that a disclaimer is relevant but not decisive. It advises members to refer only to facts they can verify, such as income reported on filed returns, and to be cautious about confirming net income or net assets. Members should not charge the lender, but may charge the client for the time involved if this is agreed in the engagement letter. The guidance also reminds members to check that their professional indemnity insurance covers this work. Lenders each keep their own list of qualifications they recognise for references.

What problems come up?

• Timing. A return filed the day before an application cannot produce documents for 72 hours.
• Age of the figures. Online calculations go back 4 years. If the lender wants an older year, contact HMRC.
• Amended returns. If a return has been amended, the lender needs the updated calculation, and the overview must agree with it.
• HMRC errors. In 2025 HMRC found incorrect Class 2 National Insurance figures on some self employed SA302s. Agent Update issue 135 said it knew of 6 cases where this caused mortgage problems, corrected those records and issued new calculations, and that calculations issued from 29 September 2025 would show the correct position.
• Coded out tax. Where some tax is collected through a PAYE code, the SA302 shows the PAYE tax deducted and the coded debt collected separately (SAM141045), which can confuse an underwriter. See coding out underpaid tax.

What does this look like in practice?

Illustration only. Mark is a sole trader whose accountant files his returns using commercial software. His lender wants 2 years of evidence. The accountant sends the 2024 to 2025 and 2025 to 2026 tax computations from the software. Mark signs in to his HMRC account and prints the tax year overview for both years, which show the tax due matching the computations and the 2024 to 2025 balance paid. The lender is on HMRC’s list of lenders that accept self printed documents, so no copies from HMRC are needed.

Because the calculation is built from the return, it is only as complete as the supplementary pages filed for each source of income.

If HMRC opens a check into your return, tax investigation insurance pays your accountant’s fees. Solar Protect cover pays up to £100,000 with no excess; it never pays tax, interest or penalties. Read how our cover works or get a quote.

Related Accountapedia entries

• Accountants’ references and income certificates
• Setting up a Self Assessment payment plan
• How to amend a Self Assessment tax return
• Do sole traders need formal accounts
• Telling HMRC you no longer need to file a return

Sources

• GOV.UK: Sa302 tax calculation
• GOV.UK: Tax calculation sa302
• GOV.UK: Mortgage providers and lenders who accept a sa302 tax calculation or t
• FCA Handbook: 6
• CIOT: Mortgage lenders
• GOV.UK: Issue 135 of agent update
• GOV.UK: Manual page SAM141045

Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 8 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.