The first question every homebuyer asks is "how much can I borrow?" The answer is more nuanced than simply multiplying your salary by four. Here is how mortgage affordability actually works in the UK.
The salary multiple
Most lenders offer between 4 and 4.5 times your annual gross income. Some specialist lenders go up to 5 or even 5.5 times for high earners or certain professions (doctors, solicitors, accountants). Joint applicants combine their incomes.
| Annual Income | 4x | 4.5x | 5x |
|---|---|---|---|
| £30,000 | £120,000 | £135,000 | £150,000 |
| £50,000 | £200,000 | £225,000 | £250,000 |
| £75,000 | £300,000 | £337,500 | £375,000 |
| £100,000 | £400,000 | £450,000 | £500,000 |
But the salary multiple is only the starting point. Lenders then apply an affordability assessment that can reduce your borrowing significantly.
The affordability stress test
Since the Mortgage Market Review in 2014, lenders must check that you can afford repayments not just at today's rate, but at a higher "stress test" rate — typically the lender's standard variable rate plus a buffer. This ensures you could still pay if interest rates rise.
The stress test means your actual borrowing power is determined by your monthly disposable income after all commitments, not just the salary multiple.
What reduces your borrowing power
Lenders scrutinise your outgoings. These are the most common factors that reduce how much you can borrow:
- Existing debts — credit cards, car finance, student loans, and personal loans all reduce your capacity
- Childcare costs — lenders factor in dependants, even if you do not currently pay for childcare
- Spending habits — lenders review bank statements for gambling, excessive spending, or reliance on overdrafts
- Credit score — a poor credit score will not necessarily reduce the amount, but it limits which lenders will accept you (and their rates may be higher)
- Employment type — self-employed borrowers typically need 2-3 years of accounts and may face stricter criteria
What increases your borrowing power
- A larger deposit — 15-20% deposits unlock better rates and higher multiples from some lenders
- Paying off debts — clearing a £200/month car payment could increase your mortgage by £40,000+
- Longer mortgage terms — a 35-year term has lower monthly payments than a 25-year term, passing the affordability test more easily
- Government schemes — shared ownership, First Homes, and lifetime ISAs can bridge the gap
- Using a mortgage broker — brokers access the full market and know which lenders are most flexible for your circumstances
Deposit requirements
Most lenders require a minimum 5% deposit, though 10-15% is more common for competitive rates. Here is how the deposit affects your options:
- 5% deposit — limited lender choice, higher interest rates (typically 1-2% above the best rates)
- 10% deposit — good range of lenders and reasonable rates
- 15-20% deposit — unlocks the most competitive rates and some higher income multiples
- 25%+ deposit — the very best rates, but the marginal benefit over 20% is smaller
Estimate your borrowing power
Use our free mortgage calculator to estimate monthly repayments at different rates and terms. It gives you a starting point before speaking to a broker or lender.
Know the property before you commit
Once you know your budget, use a PropertyReportUK report to check any property against 12+ data sources. Valuation estimates, price history, and AI analysis help you decide whether a property is worth your offer.