Most lenders will offer around 4 to 4.5 times your income as standard, with some going up to 5 or 5.5 times for higher earners or specific first-time buyer schemes. But the multiple is only half the calculation — every lender also runs an affordability stress test, checking whether you could still cover payments if your rate rose. Your existing debts, dependents, and spending habits can shrink the final number well below the headline multiple.
The headline number: income multiples
The "4.5 times your salary" rule of thumb is still the most common starting point on the UK high street, and it comes from a real regulatory backstop — the Bank of England's loan-to-income (LTI) flow limit caps how much of each lender's new lending can go out at 4.5 times income or above. But that limit is a ceiling on the lender's overall book, not a ceiling on you individually.
In practice, income multiples now sit across a wider range than the old rule of thumb suggests. Several major lenders offer up to 5 or 5.5 times income as standard, and enhanced multiples of up to 6 or 6.5 times exist for specific borrower profiles — typically higher earners in stable professions, or first-time buyers using a lender's own boosted-affordability product.
Several lenders now run named schemes offering boosted multiples specifically for first-time buyers — sometimes up to 5.5 times income where a standard applicant would only get 4.5 times. If you're a first-time buyer with a strong, stable income, it's worth asking a broker which lenders currently run one, since they change their criteria often.
The affordability stress test: the part that actually decides your case
The income multiple is only the starting point. Every UK lender is required, under FCA rules (MCOB 11.6), to check that you could still afford your repayments if interest rates rose — this is the affordability stress test, and it's usually the thing that actually determines your final offer, not the headline multiple.
Until August 2022, the Bank of England required lenders to specifically test affordability at 3 percentage points above their standard variable rate. That specific rule was withdrawn, and lenders now set their own stress methodology within the FCA framework — typically testing at somewhere between 1 and 3 percentage points above the product rate or the lender's reversion rate. The effect is broadly similar: your application has to work at a meaningfully higher rate than the one you'll actually pay, not just at today's rate.
This is precisely why two applicants with identical salaries can walk away with different offers. The lender isn't just multiplying your income — it's building a full picture of what's left over each month once your real, verified commitments are subtracted, then checking that figure still holds up under a stress-tested rate.
What actually shrinks your number
- Existing credit commitments: Car finance, loans, and credit card balances (even if paid off in full monthly) are typically factored in as ongoing commitments, reducing what's left for a mortgage payment.
- Dependents: Lenders apply a standard living-cost allowance per dependent, which comes off your assessed disposable income before the multiple is even applied.
- Buy-now-pay-later and short-term credit: Increasingly visible on credit files and increasingly scrutinised — a pattern of BNPL use can raise questions even if balances are small.
- Overtime, bonuses and commission: Often only partially counted (commonly 50%, sometimes less), and usually only once you have a consistent track record of receiving it.
- Deposit size: A bigger deposit doesn't just lower your loan-to-value — it also tends to make the affordability assessment itself less strict, since the lender's risk is lower.
Online affordability calculators (including ours) give you a genuinely useful starting estimate, but they can't replicate a specific lender's full underwriting model, credit policy, or how they treat your particular income type. Two calculators can legitimately give different answers for the same person — treat any estimate as a planning tool, not a guarantee, until a real lender has assessed your actual application.
If your income isn't a simple salary
Everything above assumes straightforward PAYE income. If you're self-employed, a limited company director, or a day-rate contractor, lenders assess your income differently — sometimes more favourably than you'd expect, sometimes more conservatively. That's a big enough topic to deserve its own guide.