The old rule of thumb is only a starting point
Most people have heard that lenders offer around 4 to 4.5 times your annual income. That's a reasonable ballpark, but it's not how affordability actually works in practice. Since the Financial Conduct Authority's mortgage market rules came into force, lenders are required to run detailed affordability checks rather than relying on simple income multiples.
This means two people earning identical salaries can be offered very different amounts depending on their spending habits, existing debts and household size. A single person with no debts and low outgoings will typically be offered more than someone with the same salary who has a car finance agreement, two children in childcare and a habit of using a credit card for groceries.
What lenders actually check
Affordability assessments generally look at your gross income (salary, bonuses, overtime if it's guaranteed and regular), and then subtract your regular outgoings. This includes existing loan repayments, credit card minimum payments, student loan deductions, childcare costs and council tax. Some lenders also factor in a general living cost allowance based on your household size and region.
Lenders are also required to run a stress test, checking whether you could still afford repayments if interest rates rose from your current deal. This is designed to prevent people taking on mortgages they'd struggle with the moment rates move. If you're on a low fixed rate now, your lender still wants to know you could cope with a higher rate later.
Your credit history matters too. Missed payments, high existing debt, or several recent credit applications can all reduce what you're offered, even if your income looks strong on paper.
Deposit size changes the equation
A bigger deposit doesn't just reduce your loan size, it can also unlock better interest rates. Lenders typically offer their most competitive rates to borrowers with a deposit of 25% or more, with noticeably higher rates for those putting down 5-10%. This is because a smaller deposit means a higher loan-to-value ratio, which carries more risk for the lender.
For first-time buyers, this creates a real trade-off. Waiting longer to save a bigger deposit could mean access to a cheaper rate, but house prices and rents may also move in that time. There's no universally right answer here, it depends on your local market and how quickly you can realistically save.
Why getting a proper estimate matters before you view homes
It's tempting to start browsing property listings before you know your budget, but this often leads to disappointment. Falling in love with a house £40,000 above what you can actually borrow wastes time and creates unnecessary stress. Getting a realistic affordability estimate first means you can view homes you can genuinely afford, and act quickly when you find the right one.
A mortgage affordability calculator can give you a starting estimate based on your income and outgoings, though a full assessment from a lender or broker will always be more precise since it accounts for your specific credit history and circumstances.
Open the matching calculator, save the result in My Toolkit and compare it with the next decision in the same journey.
FAQ
Frequently asked questions
Short answers first. Open the question if you want the detail behind the result.
How much mortgage can I get on my salary?
Most lenders offer around 4 to 4.5 times your annual income as a rough guide, but the actual figure depends on a full affordability assessment covering your outgoings, existing debts and credit history. Two people on the same salary can be offered very different amounts.
Does a bigger deposit mean I can borrow more?
A bigger deposit reduces the amount you need to borrow and can unlock better interest rates, particularly once you reach 25% or more of the property value. It doesn't directly increase your income-based borrowing limit, but it can make repayments more affordable.
What counts as income when a lender checks affordability?
Lenders generally consider your basic salary along with any guaranteed and regular bonuses or overtime. Irregular income, such as occasional freelance work or discretionary bonuses, may be given less weight or excluded depending on the lender's policy.
Sources
External links open the official source used to review this guide.