One of the first questions every first-time buyer asks is “how much can I borrow?” The answer depends on your income, your outgoings, the size of your deposit, and the lender’s own criteria. This guide explains how lenders calculate what you can borrow, what affects your borrowing power, and how to maximise the amount available to you.
For a complete overview of buying your first home, read our first-time buyer guide.
Income Multiples: The Starting Point
Most lenders use an income multiple as a starting point for calculating how much they will lend. The standard range is 4 to 4.5 times your annual gross income (before tax). Some lenders may offer up to 5 or even 5.5 times income for borrowers who meet specific criteria, such as higher earners or those in certain professions.
For a single applicant earning £35,000 per year, a 4.5x multiple would give a maximum mortgage of £157,500. For a joint application with combined income of £60,000, the same multiple would give £270,000. Add your deposit on top, and that gives you an idea of the property price you could afford.
However, income multiples are only one part of the picture. Lenders also carry out a detailed affordability assessment, which can adjust the amount up or down based on your individual circumstances.
Affordability Assessment
Since the Mortgage Market Review (MMR) in 2014, lenders are required to carry out a thorough affordability assessment on every mortgage application. This goes well beyond simply looking at your income. Lenders assess:
- Your monthly income: Basic salary, regular overtime, bonuses, commission, and any other reliable income. Self-employed applicants typically need to provide two to three years of accounts or tax returns.
- Your committed expenditure: Existing debts such as credit cards, personal loans, car finance, student loans, and childcare costs.
- Essential living costs: An estimate of household bills, food, transport, insurance, and other necessary spending.
- Stress testing: Lenders check whether you could still afford the mortgage if interest rates were to rise. They typically test at a rate several percentage points above the deal rate.
This means that even if your income supports a large mortgage on paper, your existing commitments could reduce the amount a lender is prepared to offer. Conversely, if you have very few outgoings, you may be able to borrow more than the headline income multiple suggests.
Income multiples are only the starting point. A lender’s affordability assessment looks at what you actually spend each month — and stress-tests whether you could cope if rates rise.
How to Boost Your Borrowing Power
If the amount you can borrow falls short of what you need, there are several strategies that could help:
- Pay off existing debts: Clearing credit cards, overdrafts, and personal loans before applying reduces your committed expenditure and can significantly increase the amount a lender will offer.
- Increase your deposit: A larger deposit means you need a smaller mortgage and may qualify for better rates, reducing your monthly payments and improving affordability.
- Apply jointly: Buying with a partner, friend, or family member combines both incomes, which can substantially increase the maximum mortgage available.
- Extend the mortgage term: A longer term (e.g., 35 years instead of 25) reduces the monthly payment, which can help you pass the affordability assessment. Keep in mind that a longer term means paying more interest overall.
- Use a specialist broker: Different lenders have different criteria. A broker can identify lenders who may offer higher multiples for your specific profile, such as those with more generous treatment of bonus income, overtime, or professional schemes.
- Consider government schemes: Shared Ownership requires a smaller mortgage as you only buy a share of the property. Read more in our guide to first-time buyer schemes.
What Counts as Income?
Different lenders treat different types of income in different ways. Understanding this can help you find a lender that takes the most generous view of your earnings:
- Basic salary: Always counted in full by all lenders
- Overtime and bonuses: Some lenders include 100% of regular overtime and bonuses, while others may only count 50% or require a track record of consistent payments
- Commission: Usually averaged over a period of one to three years, with different lenders using different averaging methods
- Self-employed income: Typically based on your share of net profit (sole traders) or salary plus dividends (directors). Some lenders use the most recent year, others average over two or three years
- Benefits: Some lenders accept certain benefits such as child benefit, working tax credits, or disability allowances. Each lender has its own policy
Use our affordability calculator to get an estimate of how much you could borrow, or speak to a broker who can match you with lenders that will take the most favourable view of your income and circumstances.
- Most lenders offer 4–4.5x your gross income; some stretch to 5.5x for qualifying borrowers.
- Affordability assessments consider debts, living costs, and stress-tested rates — not just income.
- Clearing existing debts before applying is one of the most effective ways to boost borrowing.
- Different lenders treat bonuses, overtime, and self-employed income differently — a broker can match you to the best fit.
- Extending your mortgage term reduces monthly payments and can help you pass affordability checks.