What Mortgage Can I Afford?

A Guide for UK Homebuyers

Buying a home is one of the biggest financial decisions you’ll ever make, and the first question most people ask is simple: “How much can I actually borrow?”

The answer isn’t just about your salary. Lenders take a deep look at your finances, from your monthly spending to your outstanding loans, before deciding what’s affordable. In this guide, we’ll explain how affordability is assessed, what you can do to increase your borrowing power, and how to budget for your new homeowner lifestyle.

Quick Takeaways:

Most lenders cap borrowing at around 4 to 5x your annual income.

Your debts and outgoings can significantly reduce the mortgage you’re offered.

Lenders 'stress test' your finances to make sure you could afford higher interest rates.

Don’t guess - a broker can give you a realistic figure before you start house hunting.

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How Do Lenders Work Out Affordability?

Every lender uses their own affordability model, but most include the following checks:

  • Income – Salary, bonuses, overtime, or self-employed earnings.

  • Outgoings – Loans, credit cards, childcare, subscriptions, and day-to-day costs.

  • Credit history – Missed payments or heavy credit usage can hold you back.

  • Deposit – Bigger deposits lower risk, which can unlock more generous offers.

  • Stress testing – Lenders model whether you could afford payments if interest rates jumped by 2–3%.

This is why two people earning the same salary may be offered very different mortgage amounts.

Mortgage Affordability Example

Let’s say you earn £40,000 per year with no debts. A lender might offer between £160,000–£200,000.

But if you’re also paying £400 per month for a car loan, your borrowing might drop closer to £140,000.

That’s why it’s so important to understand your commitments before applying. And why holding off on that car finance might save your mortgage chances!

Factors That Affect Your Mortgage Borrowing Power

Income

This is your starting point: salaries, bonuses, overtime, self-employed earnings, benefits. Some lenders are more generous than others in how they treat overtime, irregular income or benefits. This is where it pays to speak with a whole of market broker.

Outgoings

Car loans, credit cards, student loans, childcare, insurance, and even things like subscriptions all reduce your monthly “spare” income.

Credit History

A strong credit score reassures lenders that you’ve managed debt responsibly in the past. A poor one doesn’t mean you can’t borrow, but it may limit your options.

Deposit Size

The bigger your deposit, the lower the Loan-to-Value (LTV). A 10% deposit might get you a deal, but a 20% deposit could secure a much lower interest rate and increase affordability.

Stress Testing

Lenders want to see that you could still afford your mortgage if rates rise. Even in today’s market, they test affordability against higher rates to avoid future payment shocks.

How to Improve What You Can Borrow

Clear or Reduce Debts

Even a small loan or a credit card balance can make a big difference. Paying off debts before applying can increase your maximum mortgage.

Apply jointly

A joint mortgage with a partner or family member means both incomes are considered, often allowing you to borrow more. Remember, though, both parties are equally responsible for repayments.

Tidy up spending habits

Lenders often ask for three months of bank statements. Too many red flags (think gambling sites, overdraft use etc.) can raise eyebrows. A few months of “tidy” spending helps.

Budgeting for Your First Mortgage

Affordability isn’t just about what the bank will lend — it’s about what you can comfortably live with.

Factor in all costs: council tax, insurance, utility bills, service charges, and maintenance.

Keep a buffer: aim to hold a savings pot of 3–6 months’ essential costs.

Don’t overstretch: just because you can borrow the maximum doesn’t mean you should.

Tools to help you plan

Stamp Duty

Calculator

Find out exactly how much Stamp Duty you’ll need to pay when buying a property — whether you’re a first-time buyer, moving home, or investing.

Monthly Payment Calculator

Use this tool to work out your monthly mortgage repayments based on your loan amount, term and interest rate.

First-time Buyer

Guide

A comprehensive First-Time Buyer Guide, tailored to provide you with the knowledge and confidence needed to make informed decisions.

How many times my salary can I borrow for a mortgage?

Most lenders in the UK allow borrowing of around 4 to 5 times your annual income. Some specialist lenders, or certain professions, may be able to stretch a little higher. Remember, this is a starting point; your outgoings, credit history, and deposit size all play a role in the final figure.

Does my credit score affect how much I can borrow?

Yes. A strong credit score reassures lenders that you’ve managed debt well in the past. It doesn’t just impact whether you’re accepted, it can also affect how much you’re offered and the rate you’ll pay. A poor score doesn’t necessarily mean no mortgage, but you may need to work with a specialist lender and accept a lower loan amount or higher rate.

Can I get a bigger mortgage with a joint application?

Yes. A joint mortgage allows you to combine two incomes, which usually increases affordability. For many first-time buyers, this is the most straightforward way to boost borrowing power. The important thing to remember is that both applicants are jointly responsible for the repayments, if one person can’t pay, the other must cover it.

Do mortgage lenders look at my spending?

Yes. Lenders often review three months’ worth of bank statements. They’ll look for your essential spending (bills, food, travel), financial commitments (loans, subscriptions, childcare), and any patterns of discretionary spending. Occasional takeaways won’t harm your chances, but heavy overdraft use, gambling, or high-cost borrowing can raise red flags.

Need a Hand?

Working out what you can afford is a key part of your mortgage and property journey.

Book a quick intro call and we’ll help you:

  • Understand your affordability range.

  • Compare what different lenders might offer.

  • Plan a realistic budget for your new home.

Ready to explore your options?

Need Financial Planning Shopfront

Prefer to email first? No problem!

Submit your enquiry here

Need a Hand?

Working out what you can afford is a key part of your mortgage and property journey.

Book a quick intro call and we’ll help you:

  • Understand your affordability range.

  • Compare what different lenders might offer.

  • Plan a realistic budget for your new home.

Ready to get started?

Prefer to email first? No problem!

Submit your enquiry here

Need Financial Planning Shopfront

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THINK CAREFULLY BEFORE SECURING OTHER DEBTS AGAINST YOUR HOME.

YOUR HOME MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE OR ANY OTHER DEBT SECURED ON IT.

IMPORTANT: With investments, your capital is at risk. Pensions and investments can go down in value as well as up, so you could get back less than you invest.

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