Question 1

How is Stamp Duty calculated in 2026?

Accepted Answer

Stamp Duty Land Tax (SDLT) in England and Northern Ireland is charged in slices, like income tax. For a standard purchase you pay 0% on the first £125,000, 2% on £125,001 to £250,000, 5% on £250,001 to £925,000, 10% on £925,001 to £1.5 million and 12% above that. First-time buyers pay 0% up to £300,000 and 5% on £300,001 to £500,000, but lose the relief completely on a home costing more than £500,000. Buying an additional residential property adds a 5% surcharge to every band.

Question 2

Does this calculator cover Scotland and Wales?

Accepted Answer

No. Scotland charges Land and Buildings Transaction Tax (LBTT) and Wales charges Land Transaction Tax (LTT), each with different bands and reliefs. The mortgage payment maths is the same everywhere in the UK, so you can still use the repayment figures, but ignore the Stamp Duty result and check Revenue Scotland or the Welsh Revenue Authority.

Question 3

What happens when my fixed rate ends?

Accepted Answer

Most UK deals fix the rate for two or five years, after which the mortgage moves to the lender's standard variable rate unless you remortgage. This calculator lets you set the initial rate, how many years it lasts and the rate you expect afterwards. It then recalculates the payment on the balance that remains over the rest of the term, so you can see the payment shock before it arrives.

Question 4

How much can overpayments save?

Accepted Answer

Overpayments go straight to capital, so every pound stops accruing interest for the rest of the term. Most lenders let you overpay up to 10% of the balance each year without an early repayment charge during a fixed deal, but check your offer. Enter a monthly overpayment above and the calculator shows the interest saved and how many months earlier you finish.

Question 5

What is the affordability stress test?

Accepted Answer

Lenders must check that you could still pay the mortgage if rates were materially higher. There is no single mandated buffer, but testing at roughly 3 percentage points above the higher of your deal rate and the reversion rate is a useful rule of thumb. The result above shows that payment next to your income. Lenders typically lend up to about 4.5 times gross income, with some going higher for strong applicants.

Question 6

Are the figures a mortgage offer?

Accepted Answer

No. This is an estimate based on the numbers you enter. Your lender will also look at your credit file, outgoings, deposit source and the property itself, and may charge valuation, broker, legal or early repayment fees that are not included here.

Slice of the price	Rate	Taxable	SDLT
£0 to £125,000	0%	£125,000	£0
£125,000 to £250,000	2%	£125,000	£2,500
£250,000 to £925,000	5%	£75,000	£3,750
£925,000 to £1,500,000	10%	£0	£0
Above £1,500,000	12%	£0	£0
Total Stamp Duty			£6,250

UK Mortgage & Stamp Duty Calculator

Property and Mortgage Details

Stamp Duty Land Tax Breakdown

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