Mortgage Borrowing Explained: How Much Is Really Affordable?

When it comes to buying a home, one of the first questions most people ask is: how much can I borrow? It’s a sensible place to start.

Your borrowing capacity sets the parameters for your property search, monthly budget, and even your future financial security. But while many online calculators offer a quick estimate, the reality of how lenders assess mortgage affordability in the UK is more complex — and more personal.

In this guide, we break down how lenders calculate what you can borrow in 2025, what affects those decisions, and how you can increase your affordability with the right advice.

Understanding Mortgage Affordability in 2025

As of 2025, the UK mortgage market has returned to a more stable environment following years of turbulence caused by interest rate fluctuations, inflationary pressures, and regulatory changes. That said, affordability assessments remain rigorous.

The Basics: Income Multiples

Most lenders in the UK will allow you to borrow between 4 to 4.5 times your annual income, but under certain conditions — including strong credit, low debts, and stable employment — borrowing up to 6 times your income is possible. However, this is at the discretion of the lender’s underwriters and is not guaranteed.

This can vary significantly depending on:

• Whether you're applying solo or jointly

• Your profession and employment type

• Your level of existing debt

• Your credit score

• The term of the mortgage and repayment type

  
  

“The 6x income multiple often makes headlines, but it's not a right — it's a risk-assessed privilege. Lenders are ultimately looking for confidence: in your income stability, your debt profile, and your ability to withstand future financial shocks,” says David Jackson, Founder and Managing Director of Prestige Private Finance.

What Lenders Look at (Beyond Income)

Lenders aren’t just multiplying your salary and handing over the keys. Here’s what else they assess:

1. Credit Profile

Your credit score and history can dramatically influence your borrowing potential. Missed payments, defaults, or high credit utilisation can all reduce the amount you’re offered — or even lead to rejection.

2. Monthly Outgoings

Lenders now place a strong emphasis on your net disposable income — what’s left after essential costs like rent, childcare, travel, utilities, and debt repayments. High outgoings can restrict your borrowing, even if your income is strong.

3. Deposit Size

The larger your deposit, the lower the lender’s risk — and the more flexible they may be with income multiples. Typically, a 15%–25% deposit opens up more competitive deals.

4. Type of Property

Unusual property types (e.g. ex-local authority flats, thatched cottages, or new builds) can affect loan-to-value ratios and borrowing criteria.

5. Term and Product Type

Choosing a longer mortgage term (e.g. 30–35 years) can reduce your monthly repayments, improving affordability — although it increases interest paid over time. Similarly, repayment vs interest-only structures affect what lenders are willing to offer.

Can You Improve Your Affordability?

Yes — and the most effective changes often come from a combination of preparation and professional advice. At Prestige Private Finance, we work with each client to create a bespoke homeownership roadmap that looks at short-term goals and long-term resilience.

Some ways to increase your borrowing potential:

• Clear outstanding debts like personal loans and credit cards

• Improve your credit score by reducing utilisation and avoiding late payments - read more about how you can improve your credit score.

• Maximise your provable income, including bonuses, commissions or freelance earnings (where accepted by lenders)

• Consider joint applications, especially with a partner or family member

• Work with a whole-of-market broker who understands how different lenders assess affordability — and where flexibility exists

Why Does This Matter?

In a competitive housing market, knowing your exact borrowing power gives you a clear advantage. It helps you move quickly, make confident offers, and avoid unnecessary surprises further down the line.

It also ensures you’re not overcommitting. Mortgage stress — where homeowners struggle to meet repayments — has become a real risk in recent years. A tailored, realistic mortgage offer is more than a number; it’s a safeguard for your financial wellbeing.

Final Thought

Online calculators are useful — but they don’t tell the full story. Mortgage affordability in 2025 is nuanced, personalised, and increasingly reliant on good advice.

“We see clients every week who thought they couldn't buy — until they understood how lenders really think. Affordability isn’t just about numbers; it’s about strategy, structure, and knowing where the opportunities are,” says David Jackson.

Whether you’re buying your first home, remortgaging, or making a strategic investment, understanding your true borrowing power is the first step toward making smart, sustainable decisions.

Speak to a Mortgage Adviser

Want clarity on what you could borrow? Get in touch with Prestige Private Finance for a confidential, no-obligation consultation. Our advisers will help you navigate the numbers, understand your options, and build a borrowing strategy that works for you — now and in the future.