Quick answer
Not directly. Your mortgage pays the seller, and your conveyancer usually pays the stamp duty from your own money: the return and payment are due within 14 days of completion.1 What you can do is put a smaller deposit down and keep savings back for the tax, which means borrowing more. On a £350,000 home, keeping £7,500 back for stamp duty raises the loan from £297,500 to £305,000 and the loan-to-value from 85% to 87.1%, which can move you into a higher rate band.
Key takeaways
- SDLT must be filed and paid within 14 days of the effective date, usually completion.1
- The mortgage advance is used to pay the seller; the tax comes from your own funds, usually via your conveyancer.
- Borrowing more and putting less down is the only way to 'add' stamp duty, and it raises your loan-to-value.
- Crossing a loan-to-value band (such as 85% to 90%) can raise the rate on the whole loan, not just the extra.
- Late payment brings a £100 penalty, or £200 after three months, plus interest.2
Stamp duty is one of the few big buying costs that cannot be spread out. It is due almost immediately after completion, so it has to come out of the cash you bring to the deal. The real question is how to split that cash between deposit and tax.
Figures are for England and Northern Ireland (SDLT, rates from 1 April 2025). Scotland's LBTT and Wales's LTT are due within 30 days but work the same way for funding.
Worked examples: stamp duty for a home mover
| Price | England/NI tax | Scotland tax | Wales tax |
|---|---|---|---|
| £300,000 | £5,000 | £4,600 | £4,500 |
| £500,000 | £15,000 | £23,350 | £18,000 |
| £750,000 | £27,500 | £48,350 | £36,750 |
Can stamp duty be added to a mortgage?
Not as a separate item. Your lender sends the mortgage advance to your conveyancer, who uses it with your deposit to pay the seller on completion. The stamp duty return and the tax are due within 14 days of the effective date, which for most purchases is the completion date.1 Your conveyancer will normally ask you to send the tax to them before completion so they can pay HMRC on time.
So the cash you need on completion day is your deposit plus stamp duty plus fees. If you want to keep more cash for the tax, the lever is the deposit: a smaller deposit means a bigger loan, and in effect the mortgage is paying for the stamp duty.
Worked example: £350,000 home, £63,000 of savings
A home mover buys at £350,000. Stamp duty is £7,500 (2% on £125,001 to £250,000 and 5% on £250,001 to £350,000).3 Assume legal fees, survey and other costs of £3,000. The rates below are illustrations only, to show how a rate band works; use the rates your broker quotes.
| Pay stamp duty from savings | Keep £7,500 back (borrow more) | |
|---|---|---|
| Deposit | £52,500 (15%) | £45,000 (12.9%) |
| Stamp duty and fees from savings | £10,500 | £10,500 |
| Savings left over | £0 | £7,500 |
| Mortgage | £297,500 | £305,000 |
| Loan-to-value | 85.0% | 87.1% |
| Monthly payment at 4.3% (25 years) | £1,620 | £1,661 |
| Monthly payment if the higher LTV band is 4.6% | n/a | £1,713 |
Illustrative rates. Repayment mortgage over 25 years; payments rounded to the nearest pound.
At the same rate, the extra £7,500 adds about £41 a month and about £4,750 of interest over 25 years. The bigger cost is the band: at 87.1% the loan falls in the 90% loan-to-value tier, and if that tier is 0.3 points dearer, the whole £305,000 costs about £93 a month more than the 85% option.
When does borrowing more make sense?
It can make sense when the extra borrowing keeps you inside the same loan-to-value band, so the rate does not change, and the cash you keep back is a real emergency fund rather than spending money. It makes less sense when it pushes you over a band edge: check where 60%, 75%, 85% and 90% fall for your price before you decide.
If your savings are short by a small amount, compare the cost of the higher band with the alternatives: a cheaper property, a lower offer, a gifted deposit, or a first-time buyer purchase under £300,000, where no stamp duty is due at all.3
Can you pay stamp duty late, on a credit card or an overdraft?
There is no option to defer stamp duty on a normal purchase. If the return is late, the penalty is £100 if it is up to three months after the filing date and £200 after that, and interest runs on unpaid tax from the day after it was due.2
Using an overdraft or a credit card to fund the tax is risky: the debt is expensive, a lender may see it before completion, and it can affect the mortgage offer. Tell your broker before you rely on any borrowing for the completion money.
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Frequently asked questions
Can I add stamp duty to my mortgage?+
Not directly. The mortgage pays the seller and the stamp duty comes from your own money. You can put a smaller deposit down and borrow more, which has the same effect, but it raises your loan-to-value and may change your rate.
When do I have to pay stamp duty?+
Within 14 days of the effective date of the purchase, usually completion. Your conveyancer normally files the return and pays HMRC with money you send them.
What happens if I pay stamp duty late?+
A £100 penalty if the return is up to three months late and £200 after that, plus interest on the unpaid tax from the day after it was due.
How much more does it cost to borrow the stamp duty?+
At 4.3% over 25 years, an extra £7,500 adds about £41 a month. If it pushes your loan into a higher loan-to-value band, the rate on the whole mortgage can rise, which costs far more.
Do first-time buyers pay stamp duty?+
Not on the first £300,000. First-time buyers pay 5% on the part from £300,001 to £500,000, and get no relief above £500,000.
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OfficialThe figures and rules on this page are drawn from the official UK government sources below. Rates are the confirmed 2026/27 amounts. Each link opens the relevant official page in a new tab.
- GOV.UK: Pay Stamp Duty Land Tax www.gov.uk/pay-stamp-duty-land-tax Return and payment due within 14 days of the effective date.
- GOV.UK: Penalties and interest on a late SDLT return www.gov.uk/guidance/penalties-and-interest-on-a-late-stamp-duty-land-tax-return £100 up to 3 months late, £200 after; interest on late tax.
- GOV.UK: Stamp Duty Land Tax residential property rates www.gov.uk/stamp-duty-land-tax/residential-property-rates 0% to £125,000, 2% to £250,000, 5% to £925,000, 10% to £1.5m, 12% above, from 1 April 2025; first-time buyer relief to £500,000.
Verified against published UK government guidance. See also Methodology and Editorial standards.