How Much Can I Borrow for a Mortgage? (UK Affordability Guide)

The honest answer for most UK borrowers in 2024 is 4 to 4.5 times your gross annual income — capped further by an affordability stress test that simulates higher interest rates. Some lenders go higher, some go lower, but this is the working number you should use to scope your search.

The 4.5x rule of thumb

A single person earning £40,000 gross can typically borrow £160,000 to £180,000.

A couple with combined income of £60,000 can typically borrow £240,000 to £270,000.

Add your deposit, and that's your house budget.

How affordability is actually calculated

Lenders use two filters:

1. Income multiples — a cap based on your salary
2. Affordability calculation — your real income minus committed outgoings, multiplied by what they think you can afford

The lower of the two sets your borrowing limit.

Income multiples

Most mainstream lenders cap at 4–4.5x annual gross income for joint applications, slightly less for sole applicants. Some lenders go to:

• 5x for combined incomes over £80k or strong professional sectors
• 5.5x for high-earners (>£100k) or specific schemes
• 6x for some professionals (doctors, dentists, lawyers) on specific products

The Bank of England's mortgage market rules limit lenders to no more than 15% of new mortgages above 4.5x — so 4.5x is the practical ceiling for most.

Affordability calculation

Your net income minus your committed monthly outgoings = the surplus the lender thinks you have.

Committed outgoings include:

• Personal loans, car finance, BNPL
• Student loan repayments
• Child maintenance
• Council tax and utilities (estimated)
• Childcare (huge factor for many borrowers)
• School fees
• Recurring subscriptions

The surplus is then stress-tested at a higher interest rate (typically 6–8% even though current rates are 5%) to confirm you'd still cope.

Stress test mechanics

Worked example: you can pay £1,500/month at the lender's chosen "stress rate" of 7%. Over 25 years, that translates to a maximum mortgage of around £212,000.

If your income multiples allow £250,000 but the stress test caps you at £212,000, the lender lends £212,000.

This is why two earners on the same £60k can be told different borrowing limits — childcare or loan repayments swing it.

What affects your borrowing limit

Beyond the headline figures:

Boosts borrowing

• Lump-sum bonuses (typically 50–100% counted)
• Overtime / commission (typically 50% counted)
• Investment income (rental, dividends — sometimes counted)
• Multiple incomes (joint applications)
• Strong credit profile
• Larger deposit (lower LTV opens better lenders with more generous calculators)

Reduces borrowing

• Personal loans, car finance, PCP
• Student loan (treated as outgoing only — balance doesn't matter)
• Childcare costs (£1,500/month childcare can drop borrowing capacity by £80,000+)
• Credit card balances
• Other dependants
• Buy now pay later balances
• Long commute costs

Lender-by-lender differences

Different lenders weigh income components differently. A broker is invaluable here. Some examples (criteria change frequently):

• HSBC — tends to be generous on basic income, cautious on bonus
• Nationwide — strong on FTB schemes, generous on overtime
• Halifax — flexible on commission income
• Santander — good for contract income, flexible on dual income
• Skipton — strong on contractor / day-rate income
• Specialist lenders (Kent Reliance, Aldermore) — willing to consider unusual income

A broker runs your numbers through several lenders' calculators and identifies the most generous match. See Mortgage broker vs going direct to a bank.

Worked example

Joint application: Person A earning £45k, Person B earning £35k. Total: £80k.

• 4.5x income multiple = £360,000 maximum
• Net combined monthly income: ~£5,200
• Committed outgoings: £400 student loans + £200 car finance = £600
• Net affordability: £4,600
• Stress test at 7% rate, 30-year term: ~£345,000 maximum based on affordability

Lender lends the lower: £345,000.

If they had a child in nursery costing £1,200/month, affordability drops to ~£275,000.

How to maximise your borrowing capacity

• Pay off short-term debts before applying (car finance especially — lenders treat the monthly payment as an ongoing outgoing)
• Reduce credit card balances — even unused credit affects affordability
• Shop around — different lenders, different formulas
• Document overtime / commission with at least 12 months of payslips
• Consider a 35-year term — extends repayment, lowers stress-test cost (but increases lifetime interest)
• Apply jointly if not already

Things you can't change quickly

• Salary — changes when the next pay rise lands
• Job type — self-employed face stricter checks
• Number of dependants — assessable

Things that don't really help

• Larger deposit beyond LTV thresholds — once you're below 75% LTV, more deposit doesn't unlock more borrowing
• Big bank balance — savings don't directly increase income multiples
• Long employment history beyond 6–12 months in current role
• Family income / inheritance plans — only counted if guaranteed (e.g. legal trust)

Income types lenders treat differently

If your income is mostly variable, a broker who knows the market is essential.

Use our calculator to model your numbers

Try our mortgage calculator with your real figures to see what monthly payment £200,000, £250,000 or £300,000 looks like at current rates. Match that against your monthly affordability surplus.

Get a free mortgage quote — most online brokers will run multiple lender calculators in 15 minutes.

Frequently asked questions

Why does my own affordability calculator suggest more than the bank will lend? Banks layer the stress test on top of income multiples. A simple income multiple calculation often overstates what the actual lender will offer.

Does my deposit affect how much I can borrow? Indirectly — a bigger deposit lowers your LTV, which unlocks more lender choice and more generous affordability tests.

Can I borrow more if my partner adds their income? Yes — joint applications combine income. Both credit profiles also affect the application.

Do bonuses count for full multiples? Usually 50–100% depending on lender. Long-term consistent bonuses fare better than one-off windfalls.

What if I'm self-employed and only have 1 year of accounts? Most lenders want 2 years. A few specialist lenders accept 1 year of accounts plus a strong contract pipeline.

Can I borrow up to 5.5x salary? Yes, on specific products from specific lenders, usually for high earners or certain professions. A broker will know.

This article is for informational purposes only and does not constitute financial advice. Always consult a qualified mortgage adviser before making a decision.