What Is an SA302? The Tax Calculation Explained

An SA302 is the tax calculation HMRC produces from the figures on your Self Assessment tax return. It sets out your total income, the allowances that come off it, and the total tax and National Insurance you owe for the year. Most people meet it for one reason: a mortgage lender has asked a self-employed applicant to prove their income, and an SA302 is the document HMRC calls "evidence of your earnings".

This guide covers what the SA302 shows, how it differs from the tax year overview lenders usually want alongside it, how to download both, and what each number on the calculation means for a sole trader. Where it helps, we work through a real set of figures for the 2026/27 tax year so you can read your own.

Key Takeaways

• An SA302 is HMRC's tax calculation from your Self Assessment return: total income, allowances, and the tax plus Class 4 National Insurance you owe for that year.
• Mortgage lenders want two documents together, not one: the SA302 tax calculation and the separate tax year overview, which confirms the tax is recorded against your account.
• You can print both yourself from your HMRC online account, but not until 72 hours after you file, and only for the last four completed returns.
• If you file through commercial software, you print the tax calculation from that software, not from HMRC, and get the tax year overview from your HMRC account.
• The SA302 does not include your payments on account; it is the year's liability, not your full January bill.

What is an SA302?

An SA302 is the summary HMRC generates once you submit a Self Assessment return. HMRC describes the tax calculation as showing "your total income on which tax is due, any allowances and relief you have, the total amount you owe for the tax year" and how HMRC has worked that amount out.

The name is just the reference of the old paper form HMRC used to post out. The document is the tax calculation, so "SA302" and "tax calculation" mean the same thing. It is a one-year snapshot: one SA302 covers one tax year, running from 6 April to the following 5 April.

Two things it deliberately leaves out are worth flagging early. The calculation does not include your payments on account, and it does not include a Budget Payment Plan or any older unpaid tax and penalties. So the figure on an SA302 is what you owed for that tax year, which is not the same as the amount that leaves your bank on 31 January. That gap trips up people who expect the SA302 to match their actual card payment.

SA302 vs tax year overview: why lenders want both

The SA302 tax calculation is only half of what a mortgage lender asks for. The other half is the tax year overview, a separate HMRC document that lists the tax due for the year and the payments received against it. The overview is drawn from your HMRC account rather than your return, so it confirms that the figures on the SA302 were filed and recorded.

Lenders pair them for a reason. The SA302 shows the income you declared; the tax year overview shows HMRC has that same figure on file and that you have paid, or are paying, the tax on it. One without the other tells only part of the story, which is why the gov.uk list of participating lenders asks for the overview alongside the calculation.

For an application, lenders commonly ask for the last two or three years of both documents. Gather them as a set, year by year, rather than hunting for one at a time.

How to get your SA302

How you obtain the calculation depends on how you filed.

If you filed through your HMRC online account, you can print both documents yourself. Log in to your HMRC online account, go to "Self Assessment", then "More details about your Self Assessment returns and payments". From there you can view and print the tax calculation and the tax year overview for each year.

If you filed through commercial software (or your accountant did), you print the tax calculation from that software, because HMRC does not reproduce it in your account. You still get the tax year overview from your HMRC account. This is the single most common source of confusion: a self-employed applicant logs in expecting an SA302, finds only the overview, and assumes something is missing. It is not. The calculation lives in whichever system produced the return.

Two limits apply either way. You can get evidence of your earnings for the last four years once the return is sent, and you "cannot print your documents until 72 hours after you sent your tax return". If you file in late January and need the paperwork immediately, that three-day wait matters, so file with a few days in hand before a mortgage deadline.

Do lenders accept a self-printed SA302?

Yes, for the lenders that have signed up. HMRC stopped posting paper SA302s, and instead publishes a list of mortgage providers and lenders that accept tax calculations and tax year overviews printed by the customer, their agent, or their accountant. The list includes major names such as Barclays, HSBC, Lloyds Bank, Nationwide Building Society and Santander.

HMRC's own instruction is to "check that your mortgage provider accepts documents you've printed yourself" before you rely on the self-serve copies. A broker will usually know each lender's exact requirement, including how many years they want and whether they need the accountant's copy for a software-filed return. Confirm the format first; reprinting is quick, but a rejected pack at underwriting stage is not.

What the numbers on your SA302 mean

The value of an SA302 is that it shows HMRC's working, not just a final figure. Read top to bottom, it takes your income, subtracts your allowances, applies the tax bands, and adds National Insurance. Here is that sequence for a sole trader with a taxable profit of £45,000 and no other income in the 2026/27 tax year.

Start with the income tax bands for 2026/27 (England, Wales and Northern Ireland; Scotland sets its own):

The SA302 works the £45,000 profit like this:

1. Total income: £45,000. The profit from your return, before allowances.
2. Personal allowance: £12,570. Deducted first, taxed at 0%.
3. Income taxed at basic rate: £32,430 (£45,000 minus £12,570). All of it sits inside the basic-rate band, so it is taxed at 20%, giving £6,486.
4. Class 4 National Insurance. Self-employed profits also carry Class 4 NI, charged at 6% on profits between £12,570 and £50,270 for 2026/27. That is 6% of £32,430, or £1,945.80.
5. Class 2 National Insurance: nil. Because the £45,000 profit is above the £7,105 Small Profits Threshold, Class 2 is treated as paid and nothing is due.

Add the income tax and the Class 4 NI and the SA302 shows a total of £8,431.80 owed for the year. If the profit had crossed £50,270, the slice above it would be taxed at 40% and the Class 4 rate on that slice would drop to 2%, and the calculation would show those extra rows. Every figure on the page ties back to a line on your return, which is why an accurate return is the whole game.

Common misconceptions

"The SA302 is the same as the tax year overview." They are two documents. The SA302 is the calculation of what you owe; the overview confirms the tax due and payments against your account. Lenders want both, and sending one when the underwriter expects the pair delays the application.

"I filed with software, so HMRC will have my SA302." HMRC holds your tax year overview, not the calculation, when you file through commercial software. Print the tax calculation from the software you used.

"The SA302 total is my January tax bill." It is not. The calculation excludes payments on account, so a first-year sole trader can owe the SA302 figure plus a first payment on account on 31 January, which is where the well-known first-year cash-flow shock comes from.

How SparkReceipt helps

An SA302 is only as good as the return behind it, and the return is only as good as your records. The profit on your Self Assessment is your income minus your allowable expenses, so a missed expense inflates the profit, and an overstated one is a figure you cannot back up if HMRC or a lender asks.

SparkReceipt keeps that side straight. Scan or forward receipts and it reads and categorises each one, tracks your self-employed expenses and income together, and produces a tax-ready expense report with every original image attached. When it is time to file, your profit figure rests on evidence rather than a shoebox estimate, so the SA302 a lender scrutinises reflects what you earned. SparkReceipt does not file your Self Assessment or generate the SA302 itself; it keeps the records that decide the numbers on it. You can get started on the free plan.

Frequently asked questions

How long does it take to get an SA302? You can view and print it as soon as 72 hours after you file online, for any of the last four completed tax years. If you filed through software, the calculation is available from that software immediately, and the tax year overview comes from your HMRC account after the same 72-hour wait.

Can my accountant get my SA302 for me? Yes. An agent or accountant can print the tax calculation and the tax year overview on your behalf, and lenders on the gov.uk list accept the copies they print.

Why does my SA302 not match the tax I paid in January? The SA302 shows the tax and Class 4 NI due for one tax year. It excludes payments on account, so your actual 31 January payment can be higher (a balancing payment plus a payment on account) or lower (if you had already paid on account during the year).

Do I need an SA302 if I am not applying for a mortgage? Not usually. Most self-employed people only need one as proof of income for a mortgage, loan, or visa application. For everyday tax purposes, keeping your return and records is enough.

How many years of SA302s will a lender want? Commonly two or three years, but it varies by lender and product. Check the exact requirement, ideally through a broker, before you apply.

Key takeaways

• An SA302 is HMRC's tax calculation from your Self Assessment return, showing income, allowances, and the tax and Class 4 NI owed for one tax year.
• Lenders pair it with the tax year overview, a separate HMRC document; supply both, for as many years as the lender asks.
• Print both from your HMRC online account, from 72 hours after filing, for the last four years; software filers print the calculation from the software.
• Check your lender accepts self-printed copies; the gov.uk list names the participating providers.
• The SA302 excludes payments on account, so it is the year's liability, not your full January bill.