How much can I borrow for a mortgage? 7 key factors lenders check

Important: Your home may be repossessed if you do not keep up repayments on your mortgage.

If you're thinking about buying a home in the UK, one of the first questions you'll have is: how much can I actually borrow? The honest answer is that it depends on a range of factors, and every lender will assess those factors differently.

What most lenders have in common is a commitment to responsible lending. Under rules set by the Financial Conduct Authority (FCA), lenders must make a reasonable assessment of whether you can afford the mortgage, not just today, but if your circumstances change. That means there's no shortcut formula that tells you your exact borrowing limit.

What this guide does is walk you through the seven main things lenders look at, explain why each one matters, and help you understand how to present yourself in the strongest possible position.

NimbleFins is a credit broker, not a lender. This article is for information only and does not constitute financial or mortgage advice. Always seek independent advice before applying for a mortgage.

How much can you borrow for a mortgage in the UK?

Most UK lenders use income multiples as a starting point. As a general guide, most lenders offer between 4 and 4.5 times your gross annual income as their standard maximum, though some now offer higher tiers for borrowers who meet specific criteria. Under Bank of England rules, lenders are limited in the proportion of mortgages they can advance at a loan-to-income (LTI) ratio of 4.5 or above, which is why 4.5x remains the most common standard maximum across high street lenders.

That said, some lenders do offer higher multiples. HSBC, for example, currently offers first-time buyers up to 5.5 times income if you meet minimum income thresholds (at least £35,000 sole income or £55,000 joint income), with Premier customers potentially able to access up to 6.5 times income subject to individual circumstances. These are not guaranteed offers; full affordability checks apply in every case.

It's worth remembering that an income multiple is just a ceiling, not a promise. Lenders also assess your expenditure, debts, credit history, deposit, and other factors before making any decision.

Source: Bank of England LTI rules; lender criteria vary and are subject to change.

Try this mortgage affordability calculator

Get a rough picture of your house budget using this mortgage affordability calculator, but remember that lenders will carry out more extensive monthly affordability checks, so use these results as general information only.

7 key factors lenders check

Here are the main things lenders assess when deciding how much you can borrow.

1. Gross income

Your income is the foundation of any mortgage calculation. Lenders look at your basic salary, but they also consider other regular income sources, though not all income is treated equally.

For employees, basic salary is typically counted in full. Variable pay such as bonuses, overtime, and commission is often discounted; many lenders will use only a portion of these amounts, or average them over two or three years. Self-employed applicants usually need to provide two to three years of accounts or SA302 forms from HMRC, and lenders will typically use an average of those figures.

These are general patterns, not universal rules. Each lender applies its own policy and individual underwriting decisions may vary.

2. Monthly debt commitments

Lenders look at what you already owe every month. This includes loan repayments, credit card minimum payments, hire purchase agreements, and any other regular financial commitments. The higher your existing outgoings, the less you'll typically be able to borrow.

One thing to be aware of is that lenders often use the minimum monthly payment on a credit card when calculating affordability, not the amount you actually pay. Even a relatively small credit card balance can reduce your borrowing capacity. Reducing or clearing debts before applying can help improve the amount you may be offered.

Always make sure you can afford repayments before taking on any additional lending.

3. Credit score and credit history

UK credit scores are provided by three main agencies: Experian, Equifax, and TransUnion. Each uses its own scoring scale, which is why the number you see may differ depending on where you check. What matters most to lenders is not the score itself, but the underlying credit history, including whether you've missed payments, have any County Court Judgements (CCJs), or have been declared bankrupt. You can check your Experian credit report for free.

A poor credit record won't necessarily prevent you from getting a mortgage, but it may limit your options, reduce the amount available to you, and increase the interest rate you're offered. Specialist lenders exist for borrowers with impaired credit, but their products typically come with higher rates and fees.

Source: Experian. Scores are indicative; each lender sets its own credit criteria.

4. Deposit size and loan-to-value (LTV) ratio

Your deposit determines your loan-to-value ratio: the proportion of the property's value you're borrowing. A larger deposit means a lower LTV, which generally gives you access to lower interest rates and a wider choice of products. According to Halifax data, the average first-time buyer in 2024 put down a deposit of around £61,090, representing approximately 20% of the purchase price.

First-time buyers can access mortgages with as little as a 5% deposit, meaning a 95% LTV mortgage. These products exist but typically come with higher interest rates than those available to borrowers with larger deposits. Building as large a deposit as you can before applying is likely to improve both the rates available to you and the total amount you may be offered.

Data from the Bank of England from March 2026 shows average interest rates of 5.3% (variable) or 5.8% (fixed) on 95% LTV mortgages. In contrast, average interest rates on 75% LTV mortgages were 4.2% (variable) and 5.1% (fixed). The high LTV borrowing rates are close to one percentage point more expensive than lower LTV rates.

For a £200,000, 25-year mortgage, the difference between a 4% and 5% mortgage is around £114 per month. Over the full 25-year mortgage term, that rate difference would mean an additional cost of around £34,000.

5. Affordability assessment and stress testing

Beyond income multiples, lenders are required by the FCA's MCOB rules to carry out a full affordability assessment. This means looking at your actual income and expenditure, including household bills, childcare, subscriptions, and other regular outgoings, to determine whether repayments would be sustainable.

While the Bank of England withdrew its mandatory stress test requirement in August 2022, lenders still assess whether you could continue to afford repayments if your circumstances change, for example, if interest rates rise or your income falls. This is why simply meeting an income multiple is not enough on its own.

It's worth building your own stress test into your planning: could you still afford the mortgage if your rate increased by 2 to 3 percentage points?

6. Employment status and income stability

Lenders look for evidence that your income is stable and likely to continue. Permanent employment is generally viewed favourably. Probationary periods, short-term contracts, and recent job changes can sometimes make lenders more cautious.

Self-employed applicants, company directors, and contractors often face more detailed scrutiny. Lenders typically want to see a consistent earnings track record, and income that has varied significantly year to year may be averaged or partially discounted. Using the services of a qualified mortgage adviser may be particularly helpful if your income is complex.

7. Interest rates and mortgage term

The interest rate you're offered, and the length of your mortgage term, both affect how much you can borrow within lenders' affordability criteria. A lower rate means lower monthly payments, which may allow you to borrow more. A longer term also reduces monthly payments, though it increases the total interest paid over the life of the loan.

Fixed-rate mortgages give certainty over your monthly payment for the fixed period. Variable and tracker rates can go up as well as down. It's important to consider what would happen to your repayments if rates changed before committing.

These figures are illustrative only. Your actual rate and payments will depend on individual circumstances.

Using a mortgage borrowing calculator

Online mortgage calculators, such as those available on the MoneyHelper website, can be a useful starting point. They give you a rough sense of how much you might be able to borrow based on income and deposit. However, they cannot replicate a full affordability assessment. Calculators typically use simplified income multiples and do not account for your full expenditure, credit history, or the specific criteria of individual lenders.

Treat calculator outputs as indicative figures only, not as guarantees or firm offers. The actual amount any lender will consider depends on their own criteria and a full review of your circumstances.

Steps that may help improve your borrowing position

There are practical steps that may strengthen your mortgage application, though outcomes vary by individual and lender:

None of these steps guarantee a particular outcome, and whether they improve your borrowing position will depend on your full circumstances. Speaking to a qualified, independent mortgage adviser can help you understand your options before you apply. You can find regulated advisers via MoneyHelper.

Understanding the costs beyond the mortgage

The amount you can borrow is only part of the picture. Before committing to a mortgage, it's worth factoring in all the upfront and ongoing costs of homeownership, including:

These costs can add several thousand pounds to the total cost of buying, and should be part of your budget planning before you start applying.