Remortgaging can look straightforward when you are replacing one mortgage with another, but a lender still needs to decide whether the new deal is affordable. For most applications, that means looking beyond the value of your home to your income, regular financial commitments and the money left after essential spending.
What a remortgage affordability check is designed to establish
A mortgage affordability check asks whether you can reasonably keep making the required payments over the mortgage term. Under FCA responsible lending rules, lenders generally have to assess affordability using evidence rather than relying on a borrower simply saying that the payments are manageable.
For a standard remortgage assessment, lenders normally consider verified income alongside committed expenditure, essential household costs and basic quality-of-living costs. They may also apply their own lending policies, including loan-to-income limits and internal risk rules.
Your property’s equity can affect the mortgage products available because it changes your loan-to-value ratio, but equity is not a substitute for affordability. A borrower with substantial equity can still fail lender affordability if income and outgoings do not support the proposed payments.
How lenders assess your income
Lenders want income that can be evidenced and considered sustainable. For an employed applicant, this often means payslips and bank statements. Regular salary is usually straightforward to assess, while bonuses, overtime and commission may be averaged or only partly included.
Self-employed applicants may be asked for tax calculations, tax year overviews, accounts or other evidence of trading income. The period required and the way profit is assessed vary between lenders. Pension, rental and investment income can also be considered where the lender’s criteria allow it.
If the mortgage term runs into retirement, the lender may consider whether expected retirement income will support the loan. That can make pension evidence and the proposed term especially important.
What spending and financial commitments are checked
Affordability is not based on income alone. Lenders also look at money already committed elsewhere. This can include personal loans, car finance, credit card balances, maintenance payments and other regular debts. Household costs and essential spending are also part of the calculation. Different lenders use different models, which is one reason the same household can receive different affordability figures.
Where your credit history fits into the assessment
Credit history and affordability are related, but they are not the same test. Affordability measures whether your finances can support the mortgage. Credit underwriting looks more broadly at how you have managed borrowing and whether the lender is comfortable with the risk. Late payments, defaults, high revolving balances or heavy overdraft use can therefore affect a remortgage even where the monthly payment appears affordable.
Do lenders still stress-test remortgage affordability?
The Bank of England withdrew its separate mortgage-market affordability test in August 2022, but that did not remove affordability checks. FCA rules still require lenders, in relevant cases, to consider the effect of likely future interest-rate increases. Lenders have flexibility in how they design this part of their assessment, so there is no single universal stress rate used by every lender.
This means a mortgage that looks comfortable at its initial rate can still be assessed against a higher future payment. Depending on the case, the lender may consider the deal’s reversion rate, likely future products or other reasonable assumptions.
When remortgage checks can be more limited
Not every remortgage has to follow exactly the same process. FCA rules allow lenders to use modified affordability provisions in certain no-additional-borrowing cases. Broadly, the new mortgage must replace an existing regulated mortgage, remain secured on the same property and not increase the capital borrowed apart from permitted fees. Conditions also apply to recent mortgage payment history.
Where the rules apply and the lender chooses to use them, the new mortgage can be assessed by comparing whether it is more affordable than the existing mortgage or, where the current lender has indicated a new deal, more affordable than that alternative. This can help some existing borrowers move to a cheaper mortgage without being blocked by parts of a full standard assessment.
The flexibility is optional for lenders. It is not a right to a remortgage, and a lender can still apply its own underwriting policy. Taking additional borrowing will usually take the case outside this specific modified route.
A practical example
Suppose a homeowner owes £180,000 and wants to move to a new lender without increasing the balance. Their current deal is ending, and the replacement has a lower rate and lower monthly payment. If their recent mortgage payments have been up to date and the other relevant conditions are met, the new lender may be able to use the modified affordability approach rather than a full conventional assessment.
If the same homeowner wants to increase the loan to £205,000 to fund renovations, the position changes. The extra borrowing means the lender will normally need to assess whether the higher total debt is affordable using its standard criteria. That is why a simple rate switch and a capital-raising remortgage should be treated as different applications.
How to improve your chances before applying
Estimate the new monthly payment and compare it with your actual household budget, not just with your current mortgage payment. Gather income evidence early, check outstanding credit balances and make sure expected changes such as retirement or reduced working hours are disclosed accurately.
It also helps to compare lenders on criteria rather than rate alone. A slightly cheaper mortgage is of little use if the lender’s treatment of self-employed income, bonuses or existing commitments prevents you from passing its affordability model. Useful related topics to review include mortgage income multiples, remortgaging costs and improving a mortgage application.
Frequently asked questions
Do all remortgages require a full affordability check?
No. Many remortgages involve a standard affordability assessment, but certain no-additional-borrowing cases can qualify for modified rules. Whether a lender uses that flexibility depends on the case and its policy.
Can I remortgage if my income has fallen?
Possibly. Lower income can reduce the amount available under a standard mortgage affordability check, but an existing borrower moving to a more affordable deal without extra borrowing may have other options. The result depends on the lender’s criteria and your wider circumstances.
Does a good credit score guarantee I will pass affordability?
No. A strong credit record can help with eligibility and underwriting, but the lender still needs to be satisfied that the mortgage payments are affordable under the assessment it carries out.
Will a lender count all of my bonus or overtime income?
Not necessarily. Lenders usually want evidence that variable income is regular and sustainable. Some may average it over a period or use only a proportion, so treatment can differ materially between lenders.
Final thoughts
Remortgage affordability checks are designed to test whether the new mortgage can be maintained, not simply whether the property provides enough security. For most borrowers, income, debts, essential spending, future rate changes and lender-specific criteria influence the result. Some existing borrowers switching without extra borrowing may qualify for a more proportionate assessment. Knowing which route applies before you submit an application can save time and reduce the risk of an avoidable decline.