Last reviewed: June 2026
TL;DR- The mortgage stress test assesses whether the borrower could afford the mortgage if interest rates were higher than the product rate - typically 1-3 percentage points above.
- The FPC's specific 3 percentage point stress test floor was withdrawn in August 2022 - lenders now apply their own internal stress rates under FCA MCOB 11 requirements.
- The FPC retained the loan-to-income flow limit (max 15% of lending above 4.5x LTI) as the primary macro-prudential safeguard.
- The stress test is one of the most common reasons the maximum loan offer is lower than the simple income multiple calculation suggests.
Why the Stress Test Exists
The mortgage affordability stress test was introduced as part of the Mortgage Market Review in 2014. Its purpose is to ensure that borrowers can continue to afford their mortgage payments if interest rates rise during the mortgage term. The stress test protects both the borrower (from taking on a mortgage they could not sustain in a rising rate environment) and the lender (from making loans that would default if rates rise).
The rapid base rate increases of 2022-2023 validated the logic of stress testing - borrowers who had taken mortgages at very low rates in 2020-2021 and who were on variable rate products or whose fixed deals expired saw payment increases that the stress test had anticipated. Borrowers who had passed the stress test had demonstrated they could afford higher payments; those who had not been stress-tested (for example, on some pre-2014 products) were in a more difficult position.
The FPC Stress Test Floor (2014-2022)
From 2014, the Bank of England's Financial Policy Committee imposed an affordability test recommendation requiring lenders to stress test at the higher of: the product rate plus 3 percentage points; or 7% (whichever was higher). This meant that even when base rates were near zero (2020-2021), mortgages were stress-tested at 3 percentage points above the product rate, preventing excessive borrowing at artificially low rates.
The FPC withdrew this specific recommendation in August 2022, concluding that the LTI flow limit (15% cap above 4.5x) was a more efficient and proportionate safeguard and that the 3% floor interacted poorly with rising product rates in the 2022 rate environment. Withdrawing the floor did not mean no stress testing - lenders must still stress test under FCA MCOB 11 rules.
Current Stress Testing Practice
Following withdrawal of the FPC floor, lenders apply their own internal stress rates based on their own risk appetite and the FCA's requirement to assess affordability at rates that reflect the possibility of interest rate increases. Most lenders add approximately 1-3 percentage points to the current product rate in their stress calculation. The specific rate varies by lender and may change with market conditions. The practical effect on maximum loan is to reduce it below what the simple income multiple would suggest, by requiring the borrower's income to support a higher payment than the initial product rate would require.
Frequently Asked Questions
Does the stress test reduce how much I can borrow?
Yes, in most cases. The stress test requires the borrower's income to support a higher payment than the actual product rate. If the higher payment exceeds what the income can support, the maximum loan is reduced. The higher the stress rate applied, the more the maximum loan is reduced below the simple income multiple calculation. Comparing lenders with different stress rate approaches (through a broker) can sometimes improve the accessible loan amount.
Why was the 3% FPC stress test floor withdrawn?
The FPC withdrew the 3% floor in August 2022 after concluding that the LTI flow limit (which remains in force) was a more proportionate macroprudential tool. The floor interacted poorly with the 2022 rate environment - when market rates were already at 4-5%, adding a further 3% produced very high stress rates that were already well above the FPC's policy intent. The withdrawal was also supported by data showing the LTI limit was the binding constraint on high-risk lending rather than the stress test floor.
Is there any way to reduce the impact of the stress test?
Some lenders apply lower stress rate additions than others - a whole-of-market broker can identify lenders whose stress rate approach is most favourable for specific circumstances. Reducing committed expenditure (paying off debt) increases disposable income, which means the stressed payment represents a smaller proportion of available income, potentially allowing a higher loan. Choosing a longer mortgage term also reduces the monthly payment (both at the product rate and at the stressed rate), which can improve affordability under the stress test.
Does the stress test apply to buy-to-let mortgages?
For regulated buy-to-let (consumer buy-to-let) mortgages, the FCA affordability rules apply in the same way as residential mortgages, including stress testing. For unregulated investment buy-to-let mortgages, lenders apply their own rental coverage stress tests (typically requiring rental income to cover 125-145% of the mortgage payment at a stressed rate of around 5-5.5%), which serve a similar purpose to the residential stress test.
