Stamp Duty Land Tax, almost always shortened to SDLT, is the tax you pay when you buy property or land over a certain price in England and Northern Ireland. It catches a lot of buyers off guard because it is not a single flat percentage of the purchase price. Like income tax, it is built from bands, and the price is sliced across them. Understanding that slicing is what stops the bill from feeling like a mystery.

This guide explains SDLT as a mechanism. We use round illustrative numbers so the logic stays clear, then point you to a calculator for the live thresholds and rates, which change from time to time.

SDLT is a slice system, not a single rate

The most important thing to understand is that SDLT works the way income tax works. The purchase price is divided into bands, and each band has its own rate. You pay each band’s rate only on the portion of the price that falls inside that band.

This was not always the case. Before late 2014, SDLT used a “slab” system, where crossing a threshold meant the higher rate applied to the entire price. That created brutal cliff edges, where buying for one pound more could add thousands to the bill. The slab system is gone. Today, only the slice of the price sitting inside each band is taxed at that band’s rate.

That single change is why a small increase in the agreed price now produces only a small increase in tax, rather than a jump.

A worked example with round numbers

Let us use deliberately simple, illustrative figures to show the mechanism. Suppose the bands for a standard residential purchase were set like this:

  • 0% on the first £250,000
  • 5% on the portion from £250,000 to £925,000
  • 10% on the portion from £925,000 to £1,500,000
  • 12% on anything above £1,500,000

Now take someone buying a home for £400,000.

Slice of priceRangeRateSDLT on this slice
First bandFirst £250,0000%£0
Second bandNext £150,0005%£7,500
Total£400,000£7,500

Only the £150,000 above the first threshold is taxed, and only at 5%. The first £250,000 is free. The buyer’s effective rate is £7,500 divided by £400,000, under 2%, even though the “top band” they reached is 5%.

To run this on a real purchase price with the current thresholds, use our UK stamp duty calculator.

First-time buyer relief

First-time buyers get a more generous deal, designed to lower the entry cost of owning a first home. The relief raises the tax-free threshold and applies a reduced rate on the next slice, up to a maximum purchase price. Above that ceiling, the relief disappears entirely and the standard rates apply to the whole purchase.

To qualify, every buyer named on the purchase normally has to be a genuine first-time buyer, meaning you have never owned a residential property anywhere in the world. If you are buying jointly and one of you has owned before, the relief is usually lost for the whole purchase, not just half of it.

The relief also has a hard price cap rather than a smooth taper. Buy a fraction over the ceiling and you lose the relief completely, paying standard rates on everything. That is one of the few genuine cliff edges left in SDLT, so it is worth knowing exactly where the ceiling sits before you negotiate near it. Our first-time buyer SDLT calculator shows the relief and the cliff edge with current figures.

The additional-property surcharge

If you are buying an additional residential property, for example a second home or a buy-to-let, on top of one you already own, an extra surcharge is added on top of the standard rates. The surcharge applies to each band, so it raises the bill across the whole price, not just the top slice.

The test is whether, at the end of the purchase day, you will own more than one residential property. It is not about whether the new property will be rented out or lived in. A couple who jointly own their home and then buy a holiday cottage will normally face the surcharge on the cottage.

There is an important exception for people replacing their main residence. If you buy a new main home before selling the old one, you may have to pay the surcharge upfront because you briefly own two properties, but you can usually reclaim it if you sell the previous main home within a set window. The replacement rule is one of the most common sources of confusion and overpayment. Our buy-to-let stamp duty calculator applies the surcharge so you can see the difference against a standard purchase.

Scotland and Wales are different taxes

SDLT only applies in England and Northern Ireland. The devolved nations run their own equivalent property taxes with their own names, bands and thresholds.

  • Scotland charges Land and Buildings Transaction Tax (LBTT).
  • Wales charges Land Transaction Tax (LTT).

The underlying idea is similar, a banded tax on property purchases, but the thresholds, rates and reliefs differ, and the surcharge rules and first-time buyer treatment are not identical. If you are buying in Scotland or Wales, you need to use the figures for that specific tax rather than the SDLT bands.

Who pays, when, and how

SDLT is paid by the buyer, not the seller. In practice your conveyancer or solicitor handles the return and the payment as part of completing the purchase, and they usually collect the money from you in advance so they can submit and pay on time.

There is a tight deadline. The SDLT return must be filed and the tax paid within a short window after completion, currently a small number of days. Miss it and HMRC can charge penalties and interest. Because the solicitor normally manages this, most buyers never touch the deadline directly, but you should make sure the funds are with them well before completion day so nothing slips.

If a property is genuinely below the lowest threshold, there may be no tax to pay, but a return can still be required in some situations. Your conveyancer will confirm whether a nil return is needed.

What counts toward the price

SDLT is charged on the “chargeable consideration,” which is usually just the agreed purchase price. A few things can change that figure:

  • Fixtures and fittings that are genuinely chattels, such as free-standing furniture, can sometimes be valued separately and fall outside the chargeable amount, but HMRC expects realistic valuations, not inflated ones used to dodge tax.
  • Linked transactions, such as buying several properties together or in connected deals, can be added together for the rate calculation.
  • Leasehold purchases can attract SDLT on the lease premium and, for some longer leases, an additional charge based on the rent payable over the term.

For most ordinary house purchases, though, the chargeable consideration is simply the price you agreed, and the slice-based bands do the rest.

Frequently asked questions

Does buying just over a threshold tax the whole price at the higher rate?

No, not under the current system. SDLT is sliced, so only the portion of the price above a threshold is taxed at that band’s rate. The exception is first-time buyer relief, which has a hard price ceiling. Cross that ceiling and you lose the relief on the entire purchase.

Do I pay the surcharge if I am replacing my main home?

Often you pay it upfront if you complete on the new home before selling the old one, because you momentarily own two properties. You can usually reclaim the surcharge if you sell your previous main residence within the allowed window. Check the current time limit before you rely on the refund.

Is SDLT the same across the whole UK?

No. SDLT applies only in England and Northern Ireland. Scotland uses Land and Buildings Transaction Tax and Wales uses Land Transaction Tax, each with its own bands, rates and reliefs.

Can I add the stamp duty to my mortgage?

Not directly, because SDLT is due at completion and most lenders will not lend against it. In practice buyers pay it from savings alongside the deposit and fees. Some people borrow a slightly larger mortgage and use freed-up cash for the tax, but that depends on the lender, the loan-to-value, and affordability.

Primary sources