Wider context: this page tests whether you pass. For how borrowing capacity and cost move across rates, terms and deposits, see the mortgage rate sensitivity analysis.
Mortgage Stress Test Calculator
Enter your income, outgoings and mortgage details. The calculator shows your estimated monthly payment at your pay rate, then re-runs it at +1% and +3% — the classic stress scenarios — and checks each against the typical affordability ceilings lenders work to. All figures are estimates, not a lending decision.
| Scenario | Rate | Monthly payment | Share of available income | Vs typical 35–45% ceiling |
|---|
| Estimated net income (after tax & NI) | £0/month |
| Available after committed outgoings | £0/month |
| Loan amount tested | £0 |
| Rough maximum at 4.5× gross income (context) | £0 |
1. What Is the UK Mortgage Stress Test?
A mortgage stress test is an affordability check lenders perform to make sure you could still meet your repayments if interest rates rose significantly. Rather than testing whether you can afford the mortgage at today's rate, the lender asks: could you still afford it if rates increased to X%?
Mortgages are long-term commitments: a borrower fixing for two years today will remortgage when that deal expires, potentially at a higher rate. The stress test checks they have the headroom to cope.
Key fact for 2026The Bank of England's mandatory stress test — affordability at 3 percentage points above the reversion rate — was withdrawn in August 2022. UK lenders now apply their own stress margins, typically 1–3% above the pay or reversion rate, alongside the FCA's affordability rules which remain fully in force.
The three checks that shape your borrowing
| Check | What it tests | Status in 2026 |
|---|---|---|
| FPC stress test (3% above reversion rate) | Whether you could afford payments at a much higher rate | Withdrawn August 2022 |
| Lender affordability assessment (FCA MCOB) | Full income/outgoings review including a stressed rate | Still mandatory |
| Loan-to-income flow limit (4.5× LTI) | Caps the share of high loan-to-income lending across the market | Still in force |
2. What Lenders Actually Test in 2026
FCA affordability rules (MCOB)
Under the Financial Conduct Authority's Mortgages and Home Finance: Conduct of Business rules (MCOB 11), every lender must carry out a full affordability assessment before offering a residential mortgage: verifying income, accounting for committed expenditure and basic living costs, and — crucially — considering the effect of likely future interest rate rises over at least the first five years of the loan. These rules did not change in 2022 and remain the legal foundation of every stress test run today; our guide to mortgage affordability covers the full assessment.
The 2022 withdrawal of the FPC's 3% rule
From 2014, the Bank of England's Financial Policy Committee (FPC) recommended that lenders test affordability at least 3 percentage points above the reversion rate (usually the lender's Standard Variable Rate). In practice this often meant testing at 7–9% when actual mortgage rates were 2–4%. The FPC withdrew that recommendation with effect from August 2022, concluding that the loan-to-income flow limit and the FCA's affordability rules together provided sufficient protection without the extra rigidity.
Lenders' own stress margins
Withdrawing the FPC rule did not stop stress testing — it handed the calibration to individual lenders. Most now test somewhere in the range of 1–3% above the pay or reversion rate, often subject to an internal floor. The margin varies with the product: shorter fixes are commonly stressed against the reversion rate plus a margin, while fixes of five years or more are often tested closer to the actual pay rate, since the payment is locked for longer. Lenders treat these models as proprietary, so you won't usually be told the precise rate — a broker can give a clearer picture.
The loan-to-income flow limit
The FPC's other tool remains in place: lenders are limited in the share of new residential mortgage lending they can extend at loan-to-income ratios of 4.5 or higher. That is why 4.5× income remains the practical ceiling for most borrowers — some applicants can borrow more, but lenders ration those higher-LTI loans carefully. The Bank of England Bank Rate (3.75% in September 2026) then feeds into the SVRs and reversion rates that anchor most stress calculations.
3. Current Typical Stress Rates in 2026
Last checked: 7 September 2026
With the Bank of England Bank Rate at 3.75% in September 2026, reversion rates sit well above new pay rates — an SVR priced 2.5–4.0 percentage points above Bank Rate would be 6.25–7.75%, an illustration rather than a surveyed figure — see our full UK mortgage rates 2026 guide. Applying a typical stress margin of 1–3% above the relevant pay or reversion rate produces the ranges below.
| Product | Typical pay rate (September 2026) | Rate usually stressed | Indicative stress range |
|---|---|---|---|
| 2-year fixed (75% LTV) | 4.0–4.7% | Reversion rate (SVR) + margin | ~7.5–9.0% |
| 5-year fixed (75% LTV) | 4.1–4.8% | Often pay rate + 0–1% | ~4.1–5.8% |
| Tracker (Bank Rate + 0.5–1.5%) | 4.25–5.25% | Pay rate + 1–3% | ~5.25–8.25% |
| SVR / reversion rate | 6.25–7.75% (illustrative) | SVR + 1–3% or internal floor | ~7.0–9.0% |
Across the market as a whole, most stress tests in 2026 land in the region of 7–9% — but these are indicative ranges, not quotes. Each lender sets its own margin, floor and methodology, and rates move frequently.
Why long fixes can unlock more borrowingBecause a five-year-plus fix locks the payment beyond the FCA's five-year horizon, many lenders test it at or near the actual pay rate rather than a stressed reversion rate. All else equal, that lower test rate can support a larger loan — one reason longer fixes are sometimes suggested to affordability-stretched buyers.
4. Worked Examples: The Stress Test in Action
Example 1 — single earner on £40,000
Sam earns £40,000, has £250/month of committed outgoings (car finance and a credit card), and wants a £150,000 loan over 25 years at a pay rate of 4.5%.
- Estimated net income: roughly £2,690/month after tax and NI, leaving about £2,440 after commitments
- Payment at 4.5% (pay rate): ~£834/month — about 34% of available income
- Payment at 5.5% (+1%): ~£921/month — about 38% of available income
- Payment at 7.5% (+3%): ~£1,108/month — about 45% of available income, at the very edge of typical ceilings
At the pay rate Sam is comfortably inside typical ceilings, but the +3% scenario brushes the top of the 35–45% band. A lender using a full 3% margin over a high reversion rate might trim the loan; one testing nearer the pay rate probably would not. For context, 4.5× income is £180,000, so the income multiple is not the binding constraint here — the stress test is. See monthly mortgage costs in the UK for how these payments compare to typical budgets.
Example 2 — joint household on £75,000
Priya and Tom earn £45,000 and £30,000, with £600/month of commitments (a personal loan and nursery fees). They want to borrow £250,000 over 30 years at 4.5%.
- Estimated net income: roughly £5,090/month combined, leaving about £4,490 after commitments
- Payment at 4.5% (pay rate): ~£1,267/month — about 28% of available income
- Payment at 5.5% (+1%): ~£1,419/month — about 32% of available income
- Payment at 7.5% (+3%): ~£1,748/month — about 39% of available income
Even under the harshest +3% scenario the stressed payment stays inside the typical band, helped by the second income and the 30-year term. Their 4.5× multiple would allow up to £337,500, so both checks leave headroom. You can verify any of these payment figures with the mortgage repayment calculator, or model the full assessment with the affordability calculator.
These are illustrations, not offersNet incomes are approximate, tax codes and pension contributions change the numbers, and real lenders model living costs in far more detail. Treat every figure here — and in the calculator above — as an estimate.
5. How to Improve Your Stress-Test Position
You cannot change the stress rate a lender applies, so improving your position means either shrinking the stressed payment or increasing the income available to support it.
- Clear short-term debts: personal loans, car finance and card balances reduce the income available for the stressed payment. Paying them down before applying can materially lift your maximum loan.
- Reduce credit card limits: some lenders count a percentage of unused credit capacity as a potential commitment.
- Consider a longer term: a 30- or 35-year term lowers the monthly payment at both the pay and stressed rates — though total interest rises substantially.
- Add a second income: a joint application can add stress-test headroom even where the second income is modest, as Example 2 shows.
- Grow the deposit: a smaller loan means a smaller stressed payment, and a better LTV band usually means a lower pay rate too.
- Time your remortgage: if you are remortgaging rather than buying, the stress test applies again when you switch lender — the remortgage calculator shows what a new deal would cost before you commit.
Run the full affordability checkThe UKCalc Mortgage Affordability Calculator combines the income multiple, debt-to-income ratio and a stress-test simulation, so you can see which of the three checks is your binding constraint.
6. Frequently Asked Questions
Calculate How Much You Can Borrow
Use the UKCalc mortgage affordability calculator — income multiple check, debt-to-income ratio, and a stress-test simulation at your chosen rate.
Open Affordability Calculator