Finance Editor, Kael Tripton Ltd - LBS MBA - Verified against FCA Handbook: 14 June 2026
Quick answer
MCOB 11.6 requires mortgage lenders to verify your income, assess all your committed and essential expenditure, and stress test repayments against potential rate rises before granting a mortgage. Lenders cannot approve a mortgage they believe you cannot afford. As of June 2026, Consumer Duty adds further obligations on lenders to deliver good outcomes in the assessment.
What Affordability Checks Must a Mortgage Lender Do Under MCOB 11?
Direct answer
What affordability checks must a UK mortgage lender do before approving my mortgage?
Under MCOB 11.6 (handbook.fca.org.uk/handbook/MCOB/11/), lenders must verify your income, assess committed expenditure (existing debts), essential household expenditure and basic quality-of-living costs, and stress test repayments against potential interest rate rises. The lender must not approve a mortgage if the assessment shows you cannot afford it.
FCA Handbook - MCOB 11.6.2R - Verbatim Rule Text Source: handbook.fca.org.uk
A firm must not enter into a regulated mortgage contract unless, taking account of information it obtains about the customer's income and expenditure (including committed expenditure and essential expenditure), it concludes that the customer will be able to pay the sums due.
The Three Categories of Expenditure in MCOB 11.6.5
| Expenditure category | MCOB 11 definition | Examples |
|---|---|---|
| Committed expenditure | Credit and contractual commitments continuing after the mortgage | Credit cards, loans, car finance, student loan, maintenance |
| Basic essential expenditure | Expenditure for essential household needs | Food, gas/electricity, water, council tax, buildings insurance, ground rent |
| Basic quality-of-living costs | Expenditure hard to reduce, giving basic quality of life | Clothing, phone, transport beyond essential commuting |
How to Prepare for a Mortgage Affordability Assessment
Prepare your income evidence
Gather last 3 months' payslips, last 2 years' P60s (employed) or SA302 tax calculations (self-employed), bank statements showing salary credits.
List all committed expenditure
Credit card minimums, personal loan payments, car finance, student loan repayments, existing mortgage or rent, child maintenance. Lenders verify these against credit file.
Calculate your essential expenditure
Food, utilities, council tax, buildings insurance, ground rent (leasehold), essential travel. Use your actual bank statements -- estimates get queried.
Get an Agreement in Principle first
An AIP tests affordability without a full application. It identifies problems before you make an offer on a property.
If rejected -- ask for the reason in writing
The lender must tell you the application was declined. Request confirmation of which factor caused the rejection. This helps identify whether to reapply, reduce the loan, or challenge the assessment.
MCOB 11 and Self-Employed Borrowers
Self-employed borrowers face a higher documentation burden under MCOB 11.6. Lenders typically require 2-3 years of SA302 tax calculations and corresponding tax year overviews from HMRC, plus accountant-certified accounts for limited company directors. The income figure used is usually the lower of net profit (sole trader/partnership) or salary plus dividends (limited company director). Consumer Duty (PRIN 12) requires lenders not to apply affordability criteria that systematically disadvantage self-employed borrowers without justification.
Related KT guides
Frequently Asked Questions
What affordability checks must a UK mortgage lender do?
Under MCOB 11.6 of the FCA Handbook, mortgage lenders must assess whether the borrower can afford the mortgage both now and in the future. The assessment must consider the borrower's verified income, committed expenditure (existing credit commitments), basic essential household expenditure (food, utilities, council tax, buildings insurance, ground rent), basic quality-of-living costs, and the impact of likely future interest rate increases on monthly payments. As of June 2026, lenders must also consider Consumer Duty (PRIN 12) in their responsible lending assessment.
Can a mortgage lender refuse my application on affordability grounds?
Yes. Under MCOB 11.6.2, lenders must only grant a mortgage if they are satisfied the borrower can afford the repayments. If a lender believes the borrower cannot afford the mortgage, it must decline the application. The lender is not required to explain exactly why the affordability assessment failed, but it must tell you that the application was declined and, if requested, confirm whether a credit check was carried out.
What is a mortgage stress test under FCA rules?
Under MCOB 11.6, lenders must test whether the borrower could still afford the mortgage if interest rates rise. The FCA's responsible lending rules require lenders to stress test affordability at a rate above the lender's standard variable rate (SVR). The specific rate buffer has been updated over time -- as of June 2026, lenders apply their own stress test rates (the Bank of England's mandatory 3% stress test buffer above the SVR was relaxed in 2022, but lenders retain their own internal stress tests).
Can I challenge a mortgage rejection on affordability grounds?
You can request a review of the decision through the lender's formal complaints process. However, MCOB 11 gives lenders broad discretion in their affordability assessment and the FOS generally does not overturn a lender's commercial lending decision if the lender followed a proper assessment process. The FOS can investigate if the lender failed to follow its own disclosed affordability criteria, applied the assessment incorrectly, or made a factual error about your income or expenditure.
How does Consumer Duty affect mortgage affordability assessments?
FCA Consumer Duty (PRIN 12, effective July 2023) requires mortgage lenders to act to deliver good outcomes for retail customers including vulnerable customers. For affordability, this means lenders must not apply assessment criteria that are disproportionately restrictive for customers whose income or expenditure pattern is non-standard (e.g. self-employed, variable income, part-time workers). Lenders must consider whether their affordability criteria may systematically disadvantage groups of customers and adjust them if so.
Primary sources
Kael Tripton Ltd is registered with the Information Commissioner's Office under registration number ZC135439.
