Introduction: Why an SA302 Matters When You Also File a US Return
An SA302 is the tax calculation HMRC produces from your Self Assessment return, and it is the first document a UK mortgage lender asks for when your income is not a simple salary. For an American living in Britain, however, the SA302 is only half of the story. You also file a US return every year, and the two documents almost never show the same income. Consequently, an underwriter who places them side by side can see what looks like a contradiction. At TaxYork, we prepare both returns for partners, founders, bankers and investors, so we see this collision every week. This guide explains how to get your SA302, what it shows about foreign income, and how to present it alongside your American filings without delaying a large purchase.
What an SA302 Actually Is
Put simply, it is HMRC's summary of how it worked out your tax for one tax year. According to HMRC's guide to the SA302 tax calculation, it shows your total income on which tax is due, your allowances and reliefs, and the total amount you owe. It does not show payments on account you have already made towards the next bill. Furthermore, it is not your tax return. Instead, it is the arithmetic HMRC applies to the figures you submitted. Therefore, the calculation carries weight with lenders because HMRC generated it, not you.
The SA302 and the Tax Year Overview Work as a Pair
Most lenders ask for two documents for each year, not one. The first is the calculation itself. The second is the tax year overview, which shows what HMRC has charged and what you have paid for that year. Lenders use the overview to confirm that the calculation matches HMRC's own ledger. In addition, it reveals any unpaid balance, which a lender treats as a debt when it assesses affordability. As a result, an unpaid January balancing payment can quietly reduce the amount you can borrow.
How to Get Your SA302 From HMRC
Getting the document is easy once you know which route applies to you. HMRC stopped posting paper calculations automatically several years ago, so you now print them yourself or ask your adviser for them. The official GOV.UK page on getting your SA302 tax calculation sets out the steps for each filing method.
Online, Software and Paper Routes
If you file through HMRC's own online service, you sign in to your HMRC online account, open the Self Assessment section and choose the option for more detail about your returns and payments. From there, you can print the full calculation and save it as a PDF. Alternatively, if your accountant files using commercial software, the software produces the equivalent document, often labelled a tax computation. In that case, you still download the tax year overview from your own HMRC account. Meanwhile, paper filers can call the Self Assessment helpline and ask HMRC to post a copy. Many of our clients manage all of this through the HMRC personal tax account, which now sits behind the new One Login.
The 72-Hour Wait and the Four-Year Limit
Two timing rules catch people out. First, you cannot print your documents until 72 hours after you submit your return. Second, you can only download an SA302 for the last four years, although a tax year overview is available for any year. Accordingly, if your lender wants three years and one of them is five years old, you need HMRC's help rather than the portal. Additionally, a calculation only exists once the return is filed. If you have not yet filed 2025/26, your latest calculation is 2024/25, even though the 2025/26 tax year ended in April 2026.
Which Lenders Accept a Self-Printed SA302
HMRC agreed with the mortgage industry that customers and their agents could print calculations themselves. HMRC publishes the list of lenders who accept a self-printed SA302 and tax year overview, which includes most high-street banks and building societies. However, that list was last updated in June 2020, and private banks often apply their own rules. Therefore, ask your broker or relationship manager early whether a software computation is acceptable, or whether they insist on the HMRC-branded version.
What Your SA302 Shows About Foreign Income
An American resident in the UK normally reports US income on the foreign pages of the UK return. Consequently, that income flows straight into the calculation, often with a foreign tax credit sitting underneath it. Understanding how it appears helps you explain it before the underwriter asks.
US Dividends, Interest and Rental Income
Dividends from a US brokerage account, interest on a US bank account and rent from a property in America all appear as foreign income on your calculation. HMRC converts them into sterling at the exchange rate you used on the return. HMRC's guidance on tax on foreign income explains the reporting duty. Notably, lenders often discount foreign-currency income, because exchange rates move. As a result, a lender may count only part of your dollar income even though the calculation records all of it.
Foreign Tax Credit Relief on the Calculation
Where the US has already taxed income, the UK gives foreign tax credit relief, and the calculation shows that credit as a deduction from your UK tax. For example, US dividends usually suffer 15% US withholding under the treaty, and the calculation credits that against the UK charge. Similarly, US tax on American rental profit reduces the UK tax on the same rent. Underwriters rarely understand this line. Therefore, it helps to explain that a lower UK tax bill does not mean lower income; it means another country collected part of the tax first.
When the FIG Regime Hides Income From the Lender
The four-year foreign income and gains regime changes the picture for newer arrivals. If you moved to Britain after ten years of non-residence and claim relief under the foreign income and gains regime, relieved foreign income is not taxed in the UK and will not show as taxable income on your SA302. Consequently, a US citizen with substantial American investment income can look far poorer on paper than they really are. In that situation, the UK calculation understates your borrowing power, and you need other evidence, such as your US return, brokerage statements and IRS transcripts, to show the full picture.
Why Your SA302 and Your US Return Never Match
This is the problem most American borrowers do not see coming. A lender that knows you are a US citizen, or that sees dollar income on your calculation, may ask for your US return too. When it arrives, the numbers rarely agree.
Two Tax Years, Two Currencies
The UK tax year runs from 6 April to 5 April, while the US tax year follows the calendar. Therefore, your SA302 for 2024/25 and your Form 1040 for 2024 overlap by only nine months. Moreover, the US return uses dollars, and many preparers convert at the IRS yearly average rate, while the UK return converts dollar income into pounds. Partnership income adds another layer, because the US return reports your share for the firm's accounting year ending within the calendar year. As a result, two honest returns can differ by tens of thousands of pounds, and neither is wrong.
Foreign Tax Credits Make the US Return Look Empty
A second surprise follows. Most high earners in Britain use the IRS foreign tax credit rather than the earned income exclusion, so the UK tax shown on the calculation wipes out most US tax on UK income. Consequently, a Form 1040 showing half a million dollars of income can show very little US tax. An underwriter unfamiliar with cross-border returns may read that as a red flag. In our experience, a one-page reconciliation prepared by your tax adviser removes the doubt faster than any amount of email correspondence.
IRS Transcripts: The American Equivalent of an SA302
The IRS does not issue anything called an SA302, but its transcripts serve the same purpose. A tax return transcript covers the current and three prior years, while an account transcript shows filings, payments and balances. The IRS page on transcript types and how to order them explains the options. You can use the online Get Transcript service if you can pass identity checks, or Form 4506-T by post. However, postal transcripts go to the address the IRS holds, so update it first if you have moved. Our guide to IRS wage transcripts covers the account side in more detail.
Missed Tax Returns and the Mortgage Application
A mortgage application often exposes gaps in your filing history. That is uncomfortable, but it is far better to find them before an underwriter or a solicitor does.
No UK Return Means No SA302
If you never filed a UK return, there is no calculation to print. Some Americans in Britain lived on PAYE salary for years and never registered for Self Assessment, even though US dividends or gains meant they should have. Filing several late returns just before a mortgage application creates a fresh problem, because a lender sees calculations dated last week and asks why. Therefore, if you have missed UK tax returns, deal with them well before you start house hunting. HMRC's Self Assessment guidance explains who must file, and late returns carry penalties and interest that the tax year overview will then display.
Missed US Returns Surface in Source-of-Funds Checks
The US side tends to surface through anti-money-laundering checks rather than income checks. Your solicitor must trace the source of your deposit, and that trail runs through your ISA, your brokerage account and your bank statements. If those accounts never appeared on a US return or an FBAR, the paperwork you hand over documents the omission. For instance, a Stocks and Shares ISA is fully taxable in America, and the FinCEN FBAR filing guidance requires you to report it with your other UK accounts. Likewise, Form 8938 may also apply. If this describes you, our IRS Streamlined filing service and our FBAR and FATCA reporting service explain the correction routes.
Never Inflate the Figures
Occasionally, a borrower asks whether a document can be adjusted to help an application. The answer is always no. Presenting false income to a lender is a false representation under section 2 of the Fraud Act 2006, and lenders check documents against HMRC records. Moreover, the FCA's responsible lending rules in MCOB 11.6 require lenders to verify income. Instead, the honest route is to explain differences clearly and, where income is understated, to supply extra evidence.
Case Study: A London Partner Proves Income Across Two Tax Systems
The following illustrative case study combines features we see regularly. Names and details are changed, and the figures are rounded.
The Documents the Lender Asked For
Rebecca, a US citizen, has lived in London since 2016 and became an equity partner in a City law firm in 2019. As an LLP member she is self-employed for UK tax, so she files Self Assessment every year. In September 2026 she agreed to buy a £3,100,000 house in Hampstead with a £2,150,000 mortgage from a private bank. The bank asked for two years of SA302 calculations and tax year overviews, her latest US return, and evidence of her £950,000 deposit.
Her 2024/25 SA302 showed partnership profit of £412,000, US dividends of £18,000 and net Boston rental income of £24,000, giving total income of £454,000. UK income tax before credits came to about £189,300. Foreign tax credit relief of £7,900, made up of £2,700 of US dividend withholding and £5,200 of US tax on the rent, reduced it to about £181,400. Class 4 National Insurance added roughly £9,500. To give the bank the most recent year, she filed her 2025/26 return early, in October 2026, and printed that calculation 72 hours later. The tax remained payable on 31 January 2027, as the overview showed.
Reconciling the Figures
Two problems emerged. First, her 2024 Form 1040 showed adjusted gross income of about $560,000, roughly £437,000 at the IRS average rate, against £454,000 on the SA302, and US tax of almost nothing on her UK earnings. The underwriter queried both points. We prepared a short reconciliation showing the different tax years, the firm's accounting date, the exchange rates and the foreign tax credit on Form 1116. The underwriter accepted it within two days.
Second, the deposit trail showed £200,000 coming from a Stocks and Shares ISA that had never appeared on her US returns or FBARs. Rather than complete with that gap open, Rebecca instructed us to prepare corrected US filings for the open years, including the ISA income and the missing FBARs, before exchange. In addition, we noted a point the bank raised: her net income of about £263,000 fell below the £300,000 threshold for an FCA high net worth mortgage customer, so the bank relied on her net assets above £3,000,000 instead.
The Outcome
The bank issued its offer at £2,150,000, about 4.7 times the income on her SA302. Rebecca exchanged three weeks later than planned, but with both tax systems up to date and no open questions. The corrected US filings cost her a modest amount of tax on the ISA gains, which was far cheaper than leaving a documented omission in a solicitor's file.
After Completion: The US Tax Side of a UK Mortgage
Once the purchase completes, the mortgage itself creates US reporting points that a UK lender never mentions.
Mortgage Interest on the US Return
Interest on a mortgage secured on your main home can count as qualified residence interest on Schedule A, within the US limits, even when the home is in London. However, for most high earners in Britain, itemising rarely beats the standard deduction once foreign tax credits are in play. Our guide to getting a UK mortgage as a US expat covers the deduction rules and the related reporting in more detail.
Section 988 and Making Tax Digital
A sterling mortgage also creates a currency exposure that the IRS taxes. When you repay or remortgage, a fall in the pound against the dollar can produce a taxable foreign mortgage gain under section 988, even though you made no real profit. Meanwhile, on the UK side, Making Tax Digital for Income Tax now applies to many landlords and sole traders with qualifying income above £50,000. You will still receive an SA302 after your final annual return, but quarterly updates mean your records must be current all year, which also makes future mortgage applications easier.
How TaxYork Can Help
TaxYork provides comprehensive US UK tax returns preparation for high-net-worth Americans and dual nationals in Britain. We prepare your Self Assessment return and your Form 1040 together, so the figures reconcile before any lender sees them. In addition, we produce lender-ready reconciliations that explain tax years, exchange rates and foreign tax credits in plain English. Where an application reveals missed US tax returns, missed FBARs or missed reporting of an ISA or pension, we prepare the corrected filings and the supporting schedules. Our cross-border planning service also covers property purchases and the US consequences of a sterling mortgage, while our tax treaty optimisation service makes sure foreign tax credits work on both returns.
Conclusion
An SA302 is a simple document, but for an American in Britain it never travels alone. Lenders increasingly ask for the US return as well, and the two will differ because of tax years, currencies and foreign tax credits. Therefore, the best preparation is to file both returns on time, print your calculations and tax year overviews early, and keep a reconciliation ready. Above all, fix any missed returns or missed reporting before an application exposes them. For general guidance on the buying process itself, MoneyHelper's home-buying guidance is a useful starting point. For the tax side, we recommend specialist help.
Contact Us
If you are planning a property purchase and want your SA302, your US return and your supporting evidence aligned before you apply, book a consultation with our team. You can also email hello@taxyork.com or call 020 3488 8606. We work with partners, founders, bankers and investors across London and the rest of the UK.
Disclaimer
This article provides general information only and reflects the law and published guidance as at October 2026. It does not constitute tax, legal, mortgage or financial advice, and you should not act on it without taking professional advice on your own circumstances. The case study is illustrative and does not describe a real client. Lender criteria vary and change often. TaxYork accepts no liability for any loss arising from reliance on this article. Please contact us for a review of your own position.