Guide to Calculating Stamp Duty Land Tax: Transactions and Considerations

What to include when calculating SDLT

Stamp Duty Land Tax is based on the full “chargeable consideration” for a property transaction, not just the cash price. This can include money paid later, debts taken over, non-cash value, VAT, and some future payments, while genuinely separate items such as carpets or free-standing furniture can be excluded if valued fairly.

• SDLT is charged on everything the buyer gives in return for the property, including cash, assumed mortgage debt, goods, services, and release from debt.
• VAT and amounts paid for fixtures, buildings, structures, and some land-related intangible assets can form part of the chargeable consideration.
• Items outside the land transaction, such as carpets, curtains, free-standing furniture, or moveable machinery, should be excluded at a fair market value.
• If part of the price is fixed but paid later, SDLT is usually calculated on the full amount from the start.
• If extra payments depend on a future event or an unknown amount, SDLT may still be due based on assumptions or a just and reasonable estimate, with possible deferment or later adjustment.
• Care is needed where contracts mix land, chattels, business assets, or future payments, because valuation and classification can change the SDLT result.

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What to include when calculating Stamp Duty Land Tax

This page explains what counts towards the amount on which SDLT is calculated. HMRC calls that amount the chargeable consideration. In a straightforward purchase, it is usually just the price paid. But in many transactions the true consideration is wider than the cash changing hands on completion, and that can affect how much SDLT is due and when it is paid.

What this rule is about

SDLT is charged by reference to the consideration given for land or an interest in land. The key question is not simply “what is the purchase price?” but “what is the buyer giving in return for the property?”

That matters because consideration can include:

• money paid now or later
• non-cash value given in exchange
• liabilities the buyer takes over, such as debt
• amounts that depend on future events
• VAT charged on the transaction

It also matters because some items included in a sale package are not part of the land transaction for SDLT purposes. If part of the price relates to those items, a fair value must be attributed to them and excluded from the SDLT calculation.

The HMRC guidance also notes that SDLT does not usually apply where property is given as a gift and there is no chargeable consideration. The word “usually” is important, because the real issue is whether anything of value is given in return.

What the official source says

HMRC’s position is that the chargeable consideration is the total amount given for the property transaction. In a simple cash purchase, that is the price paid. But consideration is not limited to money.

According to the guidance, non-monetary consideration can include:

• goods
• works or services
• release from a debt
• taking on a debt

The guidance gives the example of joint owners separating, where one person buys out the other’s share and also takes over mortgage liability. In that kind of case, both the money paid and the debt taken on can form part of the chargeable consideration.

HMRC also says that the chargeable consideration includes anything paid for assets that form part of the land or property, including:

• buildings and structures forming part of the land
• fixtures and fittings such as bathroom and kitchen fittings
• intangible assets connected with the land, such as goodwill
• the estimated value of a commitment to do work or services
• VAT on the transaction

By contrast, items that are not part of the chargeable consideration, such as carpets, curtains or free-standing furniture, should be left out. If the sale price includes those items, the amount attributed to them must reflect their fair market value. HMRC says the same approach applies where moveable assets, such as machinery, are included in the sale of a business.

On timing, HMRC distinguishes between:

• staged or postponed payments, where part of an agreed fixed price is paid later
• contingent consideration, where a further amount is only payable if a future event happens
• uncertain or unascertained consideration, where the amount depends on an unknown future variable

For staged payments of a fixed agreed price, HMRC says SDLT is due on the full amount from the outset. There is no discount simply because some of the price is paid later.

For contingent consideration, HMRC says SDLT is calculated on the assumption that the contingency will occur. The buyer may apply to defer payment of the SDLT attributable to the contingent amount, but the tax is still charged by reference to the total consideration at the rate applicable to the original transaction.

For uncertain or unascertained consideration, HMRC says SDLT should be calculated using a just and reasonable estimate. The buyer may apply to defer payment on that uncertain part, or otherwise adjust the position once the amount becomes certain.

What this means in practice

When working out SDLT, do not stop at the headline price in the contract. You need to identify everything the buyer is giving, directly or indirectly, for the land transaction.

In practice, that means checking whether:

• the buyer is assuming any mortgage or other debt
• part of the deal is paid in kind rather than cash
• the contract includes fixtures, fittings, goodwill, works or services
• VAT is being charged
• some payments are delayed but fixed
• some payments depend on planning permission, turnover, or another future event

If the contract bundles together land and non-land items, the allocation matters. A buyer cannot simply choose an artificial figure for carpets, furniture or machinery in order to reduce SDLT. HMRC’s guidance requires a fair market value. The practical effect is that the split must be realistic and supportable.

The timing rules also matter. If the total price is fixed, SDLT is generally calculated on the full amount even if some is paid later. If part of the price is conditional or not yet quantifiable, the buyer may still need to account for SDLT by reference to that future amount, either immediately or through the deferment process described by HMRC.

This can affect cash flow. A transaction may create an SDLT liability based on value that has not yet actually been paid.

How to analyse it

A sensible way to approach the issue is to ask the following questions.

• What is the buyer giving in return for the property? Start with cash, then look for anything else of value.
• Is the buyer taking over any debt or being released from any liability as part of the deal?
• Does the price include items that are part of the land transaction, such as fixtures, structures or land-related intangible value?
• Does the price also include items outside the land transaction, such as carpets, curtains, free-standing furniture or moveable business assets?
• If so, has a fair market value been attributed to those excluded items?
• Is any part of the price fixed but payable later? If yes, HMRC’s guidance indicates it still forms part of the chargeable consideration immediately.
• Is any part payable only if something happens in future, such as planning permission being granted? If yes, treat it as contingent consideration.
• Is any part based on an unknown future figure, such as turnover? If yes, consider what would be a just and reasonable estimate.
• Is VAT payable on the transaction? If yes, HMRC says it is included in chargeable consideration.

This framework helps identify both the amount on which SDLT is charged and whether any later adjustment or deferment issue may arise.

Example

A buyer agrees to acquire a property for £500,000. On completion, the buyer pays £420,000 in cash and takes over responsibility for a £80,000 mortgage. The contract also states that carpets and free-standing furniture are included.

On HMRC’s approach, the cash and the debt taken on are both relevant when identifying the chargeable consideration. But the amount properly attributable to carpets and free-standing furniture is not part of the SDLT calculation, provided that amount reflects their fair market value. So the SDLT calculation should be based on the total value given for the land transaction after excluding a fair value for those non-chargeable items.

If the contract instead said that a further £100,000 would be payable next year regardless of events, HMRC’s guidance indicates that SDLT would still be calculated on the full fixed price from the start. If the extra £100,000 were only payable if planning permission were obtained, that would be contingent consideration and different timing rules would apply.

Why this can be difficult in practice

The difficult cases are usually not about the basic rule, but about valuation and classification.

One common issue is whether an item forms part of the land transaction or is a separate movable asset. Some things are clearly fixtures, some are clearly chattels, and some sit close to the boundary. The SDLT result can change depending on that analysis.

Another issue is the allocation of price between chargeable and non-chargeable items. HMRC’s guidance requires a fair market value, but the correct figure may still be open to debate, especially where assets are old, specialised or sold as part of a wider business package.

Future payments can also be difficult to categorise. A fixed amount paid later is not the same as an amount that only becomes payable if a future event occurs, and that is not the same as an amount whose value cannot yet be determined. The correct SDLT treatment depends on which type of provision the contract actually contains.

Finally, where future consideration is contingent or uncertain, the tax treatment may involve deferment or later adjustment. That means the SDLT position may not be fully settled on the day of completion, even though the original return still needs to be prepared on a proper basis.

Key takeaways

• Chargeable consideration is not limited to the cash price. It includes anything of value given for the property, including debt assumed and VAT.
• Amounts paid for items outside the land transaction, such as carpets or free-standing furniture, can be excluded, but only at a fair market value.
• Later payments may still affect SDLT from the outset, whether they are fixed, contingent, or based on an uncertain future amount.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Guide to Calculating Stamp Duty Land Tax: Transactions and Considerations

View all HMRC SDLT Guidance Pages Here