UK Mortgage Affordability 2026 — How much can I really afford?

Built on the same income-multiplier logic UK high-street lenders use, then layered with live Stamp Duty / LBTT / LTT figures for your region and a +3pp stress test. SDLT rates match HMRC as of April 2026; LBTT and LTT confirmed against Revenue Scotland and the Welsh Revenue Authority.

Your numbers

£
£
£
%

BoE base rate 3.75% (held Mar 2026). Typical 5-yr fix ~4.25-4.75%.

Max property price · 4.5× multiplier

£297,500

£247,500 mortgage  + £50,000 deposit

Monthly payment
£1,376
Stress (+3pp)
£1,829
Property tax
£0
Upfront cash
£50,000

"Upfront cash" = deposit + property-transaction tax. Add ~£2-3k for legal fees, survey, and mortgage arrangement.

Multiplier scenarios

Lender decisions vary by credit, job type, existing debt, and outgoings. These three multipliers show the common offer spread:

4.0× · Conservative

£270,000

Default for joint apps or weaker affordability.

4.5× · Standard

£297,500

Typical sole strong-income offer — the FPC flow-cap threshold.

5.0× · Stretch

£325,000

Specialist lenders, professional schemes, very strong affordability.

How the numbers are built

The tool chains three calculations:

  1. Income multiplier — gross household income × 4.0 / 4.5 / 5.0 = max loan. Conservative to stretch.
  2. Max price = max loan + your deposit.
  3. Property-transaction tax — SDLT (England & NI), LBTT (Scotland), or LTT (Wales), applied to max-price-at-4.5× with FTB relief where applicable.

The monthly payment uses the standard UK repayment-mortgage formula M = P × [c(1+c)n] ÷ [(1+c)n − 1] where c is the monthly rate and n is term-in-months. The stress-tested figure repeats the calculation at your rate + 3 percentage points — a rule-of-thumb buffer some lenders still apply since the FCA's mandatory stress test was removed in August 2022.

Every SDLT, LBTT and LTT band used here is verified against the official publication on 20 April 2026 — see the FAQ below for the exact schedules. Rates change at UK Budgets and at the Scottish and Welsh Budget cycles; if you land here after such a change, our 30-item test suite and source-dated comments make it a two-edit fix.

Sources

FAQ

How much can I realistically borrow for a UK mortgage?
Most UK lenders offer 4 to 4.5 times your gross annual income, or combined income for joint applications. Some specialist lenders and certain professional schemes stretch to 5× or 5.5×. Final offer depends on credit score, existing debt, outgoings, and the stress-tested affordability at your lender.
What is the 4.5× income cap?
The Bank of England's Financial Policy Committee limits how much of any lender's new mortgage lending can be above 4.5 times income — not more than 15% of a large lender's flow (raised to 20% for some lenders after 2024). It's a portfolio cap, not a per-borrower rule. Individual borrowers can exceed 4.5× if the lender has capacity and affordability is strong.
What is the SDLT rate in England and Northern Ireland in 2026?
From 1 April 2025 the nil-rate band dropped back to £125,000 (from the temporary £250,000). Current rates: 0% up to £125k, 2% £125k-£250k, 5% £250k-£925k, 10% £925k-£1.5m, 12% above £1.5m. First-time buyers: 0% up to £300k, 5% £300k-£500k, no relief above £500k.
What is LBTT in Scotland in 2026?
Scotland's Land and Buildings Transaction Tax (LBTT): 0% up to £145k, 2% £145k-£250k, 5% £250k-£325k, 10% £325k-£750k, 12% above £750k. First-time buyers get the nil-rate threshold raised to £175,000 (max saving £600). The Scottish Budget 2026-27 kept rates unchanged.
What is LTT in Wales in 2026?
Wales uses Land Transaction Tax (LTT): 0% up to £225k, 6% £225k-£400k, 7.5% £400k-£750k, 10% £750k-£1.5m, 12% above £1.5m. Rates unchanged since 10 October 2022. Wales has no first-time-buyer relief — the nil-rate threshold is already the UK's highest.
Why is the stress test at +3pp?
Until August 2022, FCA rules required lenders to stress-test at revert rate + 3pp to protect borrowers against rate rises. The rule was removed, but lenders still use buffers of 1-3pp — +3pp is the conservative end and a useful personal sanity check.
What mortgage rate should I use?
As of April 2026 the Bank of England base rate is 3.75%, and typical 5-year fixed residential mortgage rates are around 4.25-4.75% for 75-80% LTV. The tool defaults to 4.5% as a mid-market indicative rate — check https://www.moneyfactscompare.co.uk or your broker for live deals.
How much cash do I need upfront beyond the deposit?
Beyond the deposit you'll need property-transaction tax (SDLT/LBTT/LTT) if applicable, plus ~£1,500-£2,500 for legal fees and surveys, ~£100-£400 for mortgage arrangement, and removal/stamp/insurance costs. This tool shows the deposit + property tax; add £2-3k on top for the rest.