Figures and rules read 22 October 2026

Can You Add Stamp Duty to Your Mortgage?

Sometimes — but it is a lending decision, not a tax rule. There is no government scheme that lets you defer SDLT; whether it can be borrowed depends on the lender and the loan-to-value.

What is actually happening

You are not adding the tax to the tax bill — you are borrowing more against the property and using part of the loan to pay the tax. The lender has to agree to a bigger loan, and the extra borrowing counts against the affordability check and the loan-to-value.

Why lenders are cautious

A higher loan-to-value usually means a higher rate, and if the extra borrowing pushes you into the next LTV band the whole loan can get more expensive — not just the extra amount.

The timing problem

SDLT is due within 14 days of completion, before any later remortgage. Borrowing more at completion has to be arranged as part of the original mortgage application, not afterwards.

The alternatives

Some buyers use a family loan, a longer completion date to save more, or a lower purchase price. None of these changes the tax itself.

Where to go next

• Work out how much you need
• Or whether any tax is due at all

Rules read from GOV.UK, Revenue Scotland and GOV.WALES on 22 October 2026. General information only — not legal or tax advice.

More UK stamp duty calculators

• SDLT calculator — England and Northern Ireland
• LBTT calculator — Scotland
• LTT calculator — Wales
• Work out what you may have overpaid
• At what price does stamp duty start?
• LBTT vs SDLT — the same house, two systems
• Guides — when to pay, what changed, borrowing it