There is a conversation that happens in January and a conversation that happens in June, and most self-employed people never realise they are the same conversation.

In January, your accountant does what you pay them to do. Every allowable expense claimed, capital allowances used, salary kept low, dividends kept sensible, profit left in the company where the tax man cannot reach it. You sign the return, admire the tax bill, and feel like a grown-up.

In June, you sit in front of a mortgage lender, and the lender asks for the very document that tax efficiency produced: the SA302. That form summarises your declared taxable income for the year, and it is the number most lenders will use to decide how much you can borrow. Not your turnover. Not what lands in your business account. The number your accountant spent all year making as small as legally possible.

We have written before about what it feels like when a lender says no to a self-employed applicant, and the pattern behind a lot of those declines is not bad credit or bad luck. It is good accounting pointed in the wrong direction.

The number lenders actually use

Lenders do not have one rule for the self-employed, they have one rule per business structure, and the differences matter more than most applicants expect.

How you trade	What most lenders assess	The common surprise
Sole trader	Net profit from your tax return	Expenses you claimed come straight off your borrowing power
Limited company director	Salary plus dividends drawn	Profit left in the company is often invisible
Director, specialist lender	Salary plus your share of net profit	Retained profit counts, but fewer lenders offer this
Day-rate contractor	Day rate multiplied out to an annual figure	Some lenders treat you like an employee on your gross rate
CIS subcontractor	Gross income on CIS statements	A handful of lenders ignore the net profit figure entirely

Two identical businesses, each generating the same real income, can support very different mortgages depending on which row they sit in and which lender reads the file. This is why the choice of lender is not a detail. It is most of the decision.

A worked example

Take a limited company with £160,000 of turnover. After costs the company makes £85,000. The director takes a £12,570 salary and £38,000 in dividends, and leaves the rest in the business, which is exactly what most accountants would suggest.

A mainstream lender assessing salary plus dividends sees income of £50,570. At a typical multiple of 4.5 times income, that supports borrowing of about £227,000.

A specialist lender assessing salary plus share of net profit sees something closer to £97,000 of income, supporting borrowing of around £437,000.

Same company. Same year. Same director. The difference between the two assessments is over £200,000 of borrowing, and the applicant did nothing differently except walk through a different door. The figures are illustrative, but the shape of them is real, and it is the single most useful thing a self-employed borrower can understand before applying anywhere.

The two-year average, and the year that drags you down

Most lenders want two years of figures and will average them. A few will work from the latest year alone, and a few will accept a single year of trading. That sounds like flexibility until you notice the catch: if your latest year is lower than the year before, almost every lender abandons the average and uses the lower figure on its own.

So a business that did £70,000 then £50,000 is assessed on £50,000, while a business that did £50,000 then £70,000 might be assessed on £60,000. Growth is averaged, decline is punished. If you had one soft year because you took time off, invested in kit, or lost a client and replaced them, the file needs to explain that, because the numbers alone will not.

Planning eighteen months out

None of this means tax efficiency is a mistake. It means a mortgage application is a project with a lead time, and the planning window is roughly the two accounting years before you apply.

If you know a purchase is coming, that is the time to talk to your accountant about the balance between tax saved and borrowing lost. Declaring more profit means paying more tax, and sometimes that trade is worth it and sometimes it is not. A director who pays an extra few thousand in tax to unlock an extra £100,000 of borrowing on a home they intend to stay in may consider that cheap. A director who does it to stretch onto a bigger buy-to-let may not. The point is to do the arithmetic on purpose rather than discover it in an underwriter’s email.

And if the accounts are already filed and the purchase cannot wait, the answer is usually not a bigger deposit or a smaller house. It is finding the lender whose method fits your structure, which is exactly the territory we covered in the broker who read my accounts. An adviser who reads company accounts properly will often find income a high-street application form has no box for.

What not to do

One warning, because it comes up every time this subject does. The fix for a low declared income is never to declare income you did not earn, and it is never to “adjust” documents. Lenders cross-check SA302s and tax year overviews directly against HMRC records, and a mismatch is not a decline, it is a fraud marker with a six-year memory. Slower and honest beats fast and flagged, every time.

Frequently asked questions

Can I get a mortgage with only one year of accounts? Yes, with a smaller pool of lenders, and the file needs to be clean elsewhere. Two years opens most of the market, three years opens effectively all of it.

Do lenders count retained profit in my company? Some do, most do not. The lenders that assess salary plus net profit share are mostly specialist or intermediary-only, which in practice means you reach them through a broker rather than a branch.

My dividends vary a lot year to year. Is that a problem? Variation is normal and lenders expect it. What unsettles underwriters is a latest year sharply below the previous one with no explanation, so provide the explanation before they ask.

Does turnover matter at all? Barely, on its own. A lender might glance at it for context, but affordability is built on taxable income or drawn income. A £300,000 turnover with £20,000 of declared profit is, to a lender, a £20,000 income.

The self-employed do not get worse mortgages because lenders dislike them. They get worse mortgages when the paperwork built for one audience is handed, unedited, to a completely different one. Know which number your structure produces, know which lenders read it generously, and give yourself the two-year run-up to shape it. The tax return and the mortgage application are the same document. Write it once, for both readers.