Mortgage Affordability Rules Are Changing — and Contractor FTBs Should Take Note

The rule changes

The FCA updated its mortgage affordability rules in 2025, giving lenders more flexibility to reduce their internal stress-test rates. These stress tests — which determine whether a borrower could still afford their mortgage if rates rose — had been set at a fixed floor under previous guidance. The rule change allows lenders to calibrate those floors more responsibly to current market conditions.

Santander was the first major high-street bank to act on this flexibility, lowering its internal stress-test rate in a move that enabled some borrowers to access between £10,000 and £35,000 more than they could have qualified for under the old criteria. Santander's David Morris described the change as helping the market move “in the right direction,” with particular benefit for first-time buyers who had previously been shut out by conservative stress-testing.

The Mortgage Guarantee Scheme continues to provide further structural support for higher loan-to-value purchases, meaning the environment for contractor FTBs has genuinely improved on multiple fronts simultaneously.

Why income assessment matters more than stress rates for contractors

Here is where many commentary pieces on these rule changes miss the most important point for contractors specifically. Even when a lender lowers its stress-test rate, the income figure entered into that calculation still determines how much you can borrow. A lower stress rate applied to an undervalued income figure still produces an undervalued result.

The core issue for contractors is that most high-street lenders default to SA302 net profit when assessing self-employed income. For a limited company contractor, this typically captures a salary plus dividend combination that dramatically understates real earning capacity. A contractor billing £450 per day is generating gross contract income in excess of £100,000 per year — but a net profit figure might show £35,000 or £38,000 after salary, dividends, and retained earnings are separated out.

Specialist contractor lenders assess income differently: they annualise the current day rate directly, typically using the contract rate multiplied by 46 working weeks. That is the figure that goes into the affordability calculation — not the SA302 total. When the stress rate also falls, the combination is particularly powerful.

Worked example

Consider a contractor billing £450 per day, with a net profit on their SA302 of £38,000.

Standard high-street assessment: income assessed at £38,000 × 4.5 income multiple = maximum loan of £171,000.

Specialist contractor assessment: £450 × 5 days × 46 weeks = annualised income of £103,500 × 4.5 income multiple = maximum loan of £465,750.

That is a difference of £294,750 — from exactly the same contractor, on exactly the same income, applying in exactly the same week. The stress-rate reduction from the affordability rule changes applies on top of this. For a contractor FTB, getting the income assessment right is by far the more valuable piece.

How to take advantage now

The current market represents one of the most accessible environments for well-informed contractor FTBs in years. Affordability rule changes are reducing stress thresholds. Specialist lenders are assessing income correctly. The Mortgage Guarantee Scheme is supporting higher-LTV products. And rates have come down from their 2023 peaks.

The practical steps are straightforward: engage a specialist contractor mortgage broker to get a proper assessment using day-rate annualisation; understand which lenders apply contractor-specific underwriting criteria rather than standard self-employed criteria; and ensure your application is structured correctly before submission to avoid unnecessary declines that appear on your credit record.

The opportunity exists. Getting the right advice is what determines whether you can access it.

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Category: First-Time Buyer & Homebuying Journey