What Size Mortgage Can I Get When Remortgaging?

Income Multiples: The Starting Point

The income multiple is the most widely quoted affordability metric, and for good reason: it gives a quick, intuitive sense of scale. Most mainstream lenders — the major high-street banks and building societies — lend at 4x–4.5x gross annual income for a standard employed borrower. On a salary of £40,000 this produces a maximum loan of £160,000–£180,000. On £60,000 the range is £240,000–£270,000. On £80,000 it rises to £320,000–£360,000.

Specialist lenders and professional mortgage schemes extend to 5x–5.5x for qualifying borrowers. At 5.5x a borrower earning £60,000 could access a loan of £330,000 — £60,000 more than at 4.5x on the same income. This additional capacity makes a material difference in high-cost areas where the gap between a standard 4.5x loan and a property price is significant. Eligibility for enhanced multiples typically requires a strong credit history, stable employment in a recognised profession, and a debt-to-income ratio within lender guidelines.

Joint applications combine both incomes for multiple purposes. Two earners on £35,000 each produce a combined income of £70,000, supporting a loan of £280,000–£315,000 at 4x–4.5x — broadly similar to what a single higher earner would access. Lenders vary in how they treat the second applicant's income: some include 100% of both salaries, others apply a reduced multiple to the lower earner's income to reflect risk. A broker will identify which approach produces the most favourable outcome for your specific income split.

Income multiple caps set by the Prudential Regulation Authority (PRA) require that no more than 15% of a lender's new residential mortgages can be at loan-to-income (LTI) ratios above 4.5x. This systemic limit means that even lenders who theoretically offer 5x+ have limited capacity to do so, and high-multiple products may be allocated on a first-come-first-served basis or only to the strongest applications. Applying early in a rate-cut cycle — when demand for high-multiple products increases — gives the best chance of approval.

How Stress Testing Reduces Your Maximum Loan

Stress testing is the mechanism by which lenders check that you could afford the mortgage if rates rose above the current level. All regulated lenders in the UK are required to apply a stress test, though the specific rate used varies. Most lenders add a buffer of 2%–3% above the reversion rate (the rate you would pay if you moved off the initial deal) to arrive at the stress rate, which is often in the range of 6.5%–8.5% depending on the lender and prevailing rate environment.

The practical effect of stress testing is to reduce the maximum loan available below what the headline income multiple suggests. A borrower earning £60,000 at 4.5x income could theoretically borrow £270,000. But if the lender stress-tests at 7.5%, the monthly payment on £270,000 would be approximately £2,000. The lender will only approve the loan if your net income after existing commitments can comfortably support this level of payment. Borrowers with high existing debt repayments — car finance, credit cards, personal loans — will find their maximum mortgage reduced more significantly by stress testing than those with minimal existing commitments.

The Bank of England removed its hard affordability test recommendation in August 2022, which had previously required lenders to test borrowers at the standard variable rate plus 3%. Lenders now set their own stress rates within FCA guidelines, leading to more variation in practice. Some lenders have become more generous in their stress testing as a result, which is one reason why using a broker to identify the most favourable lender for your specific income and debt position is increasingly valuable.

LTV, Equity and How They Affect Borrowing

Loan-to-value ratio (LTV) determines both your access to the best rates and, in some cases, the maximum loan a lender will offer. Most lenders cap mortgage lending at 85%–90% LTV, meaning the loan cannot exceed 85%–90% of the property's value. For a remortgage rather than a purchase, lenders often apply tighter caps — 85% LTV is a common maximum for remortgages, and many specialist or high-multiple products are only available up to 75%.

Property equity therefore acts as a constraint on how much you can borrow. If your property is worth £300,000 and your existing mortgage balance is £200,000, your current LTV is 67%. Remortgaging to raise additional capital — for home improvements, debt consolidation or other purposes — increases the LTV. Borrowing an additional £25,000 to reach £225,000 takes your LTV to 75%, which remains within the range of most competitive products. Borrowing an additional £55,000 to reach £255,000 takes your LTV to 85%, where product choice narrows and rates increase.

The equity cushion also provides protection against property value fluctuations. A remortgage at 85% LTV leaves a 15% equity margin — if property values fell by 10%, your LTV would rise to 94%, which could cause problems at the next remortgage. Borrowing conservatively — keeping LTV at 75% or below where possible — provides resilience against market movements and access to better rates simultaneously.

Negative equity — where the outstanding mortgage exceeds the property value — is a specific constraint that prevents remortgaging in most cases. Lenders will not provide a new mortgage on a property in negative equity except in limited circumstances, such as Help to Buy schemes or specific lender programmes for existing customers. If you are in or near negative equity, specialist advice is essential before attempting to remortgage.

Credit Score, Debts and Other Factors

Credit history has a significant impact on both the availability of remortgage products and the rate you are offered. Borrowers with excellent credit scores — reflecting a history of on-time payments, low credit utilisation and no adverse markers — access the full product range at the best available rates. Those with mild adverse history — one or two late payments, a small default over three years ago — may still access mainstream products but at higher rates or with a smaller selection of lenders. Significant adverse markers — CCJs, bankruptcies, recent mortgage arrears — require specialist lenders and typically result in rates 1%–3% above the standard market.

Existing debt repayments reduce the maximum mortgage a lender will offer by reducing your disposable income. Most lenders include credit card minimum payments, personal loan repayments, car finance payments and student loan repayments in their affordability calculations. A borrower with £800 per month in existing debt commitments will be assessed as if their available income for mortgage purposes is £800 per month less than their gross income allows. Clearing or reducing existing debts before applying for a remortgage is one of the most effective ways to increase your maximum loan.

Employment type affects both the maximum loan and the complexity of the application. Employed borrowers on a fixed salary are the easiest case — most lenders will accept a payslip and P60 with minimal additional documentation. Self-employed borrowers need two to three years of accounts or SA302 tax returns. Contractors are typically assessed on annualised day rate. Zero-hours workers, those with irregular income or those on probation at a new employer may face additional scrutiny or reduced maximum loans. Identifying the right lender for your specific employment situation is a core broker service.

Property type and location can also affect the maximum loan. Flats above four storeys, non-standard construction, properties in certain flood risk zones, short leaseholds and rural properties with large plots of land may all result in reduced lender appetite or lower valuations than comparable conventional properties. These factors reduce the maximum LTV a lender will accept and therefore the absolute maximum loan on a given property value. A broker familiar with the specific property type will know which lenders are most receptive.