Stamp Duty Land Tax: Debt Assumption and Release Guidelines Under FA03/SCH4/P

SDLT when a property transfer includes taking over a mortgage or other debt

If you take on a mortgage or other debt when a property is transferred, that debt can count as chargeable consideration for Stamp Duty Land Tax, even if little or no cash is paid. The rule looks at whether responsibility for the debt has shifted in substance, and in joint ownership cases the amount usually follows each person’s ownership share rather than the full loan balance.

• SDLT is not limited to cash paid for a property; taking over an existing mortgage or other debt can also be taxed as consideration.
• A person may be treated as assuming debt if they become personally liable, if the seller is released from liability, or if they agree to indemnify the seller.
• This commonly affects transfers of mortgaged property between spouses, civil partners, co-owners, or family members, including adding or removing a joint owner.
• Where the property is jointly owned before or after the transfer, the assumed debt is generally worked out by reference to each person’s ownership share, not automatically the whole mortgage.
• For example, if someone acquires a 50% share in a mortgaged property, they are usually treated for SDLT purposes as assuming 50% of the debt, plus any cash they pay.
• The SDLT treatment does not change the lender’s rights, so a borrower may still be fully liable under the mortgage even if only part of the debt counts for SDLT.

Scroll down for the full analysis.

SDLT and taking over a mortgage or other debt on a property transfer

This page explains when an existing debt, such as a mortgage, counts as chargeable consideration for Stamp Duty Land Tax. The point matters because SDLT is not limited to cash paid to the seller. If the person acquiring the property takes on liability for a debt, that can itself be treated as part of the price for SDLT purposes.

What this rule is about

When land is transferred, the buyer may not pay only cash. They may also agree to take over an existing loan secured on the property, or otherwise relieve the seller of liability for that debt. The SDLT rules treat that assumption of debt as chargeable consideration.

The underlying idea is simple. If the seller is freed, wholly or partly, from a debt because of the transfer, the buyer has given something of value. For SDLT, that value can be taxed in the same way as money paid directly.

This issue often arises on transfers of mortgaged property, including transfers between joint owners, transfers into joint names, and transfers where one co-owner is removed or added.

What the official source says

The source states that paragraph 8 of Schedule 4 to Finance Act 2003 treats the assumption of liability for an existing debt as chargeable consideration for SDLT.

According to the source, a transferee assumes debt where the rights or liabilities of any party to the transaction change in relation to that debt. This is wider than simply signing a new personal covenant to the lender.

In particular, the source says the transferee assumes liability where:

• the transferee gives a personal covenant for the debt,
• the transferor is released from their personal covenant, or
• the transferee agrees to indemnify the transferor against that liability.

The source also explains a special rule in paragraph 8(1B) for transfers of property subject to debt where the transferee assumes liability for all or part of the debt and, before or after the transfer or both, the property is jointly owned.

That rule is intended to prevent an unfair result. Without it, there was concern that a person acquiring only a share of a property might be treated as assuming the whole debt, because mortgage liability is often joint and several. The rule therefore says that, in working out how much debt each person has assumed, each person’s liability is taken to be the proportion of the debt that matches their ownership share in the property.

What this means in practice

If you acquire land subject to an existing mortgage or other debt, SDLT may be calculated not only by reference to any cash you pay, but also by reference to the debt you take on.

This can apply even if no money changes hands. A common example is a transfer of a share in a home between spouses, civil partners, co-owners, or family members where the property is mortgaged. If the incoming owner takes on responsibility for part of the mortgage, that assumed debt may be chargeable consideration.

The rule is not confined to cases where the lender formally substitutes one borrower for another. The source makes clear that the SDLT analysis looks at whether liabilities have changed in substance. If the seller is released, or if the buyer agrees to stand behind the debt by indemnifying the seller, that can amount to assumption of debt.

Where the property is or becomes jointly owned, the amount brought into account is not automatically the full mortgage balance. Instead, the legislation attributes the debt assumed by each person according to their ownership share in the property. That is especially important on transfers of part shares.

How to analyse it

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

• Is there an existing debt connected with the property, such as a mortgage?
• As a result of the transaction, does the transferee take on liability for that debt in any form?
• Has the transferor been released from liability, wholly or partly?
• Has the transferee agreed to indemnify the transferor in respect of the debt?
• Is the property in joint ownership before the transfer, after the transfer, or both?
• If there is joint ownership, what ownership share does each person hold?

If the answer shows that liability for the debt has shifted to the transferee, the debt assumed can form part of the chargeable consideration.

If joint ownership is involved, the source indicates that the amount of debt treated as assumed should be aligned with the person’s share in the property, rather than automatically with the full legal liability under the loan documents.

This is a tax rule about measuring consideration. It does not change the lender’s rights under the mortgage. A borrower may still be jointly and severally liable to the lender even though, for SDLT purposes, only a proportion of the debt is treated as assumed.

Example

Illustration: A property is owned solely by V and is subject to a mortgage. V transfers a 50% share to P, and after the transfer the property is owned equally by V and P. P becomes jointly liable in relation to the mortgage.

On the source material, the key SDLT point is that P should not automatically be treated as assuming the whole mortgage debt merely because mortgage liability may be joint and several. Where the special joint ownership rule applies, P’s assumed liability is taken to be the proportion of the debt that corresponds to P’s 50% ownership share.

If there is also cash paid, that cash would need to be considered alongside the debt assumed when working out total chargeable consideration.

Why this can be difficult in practice

The legal test is wider than many readers expect. People often look only for a formal assumption of the mortgage, but the source shows that SDLT can also be triggered where the seller is released or where the buyer gives an indemnity.

Another difficulty is the difference between lender liability and SDLT treatment. Under mortgage law, parties may be jointly and severally liable for the whole debt. But for SDLT, the special rule in joint ownership cases may allocate assumed debt by reference to beneficial ownership shares instead. That means the tax analysis may not mirror the banking documents exactly.

It can also be important to identify the actual ownership shares after the transaction. If the shares are not equal, or if the beneficial ownership differs from the legal title, the analysis may require care.

The source material here deals with the principle that assumed debt is chargeable consideration and with the proportionate rule for joint ownership cases. It does not set out every procedural or computational detail, so the facts of the transaction still matter.

Key takeaways

• For SDLT, taking on an existing debt can count as chargeable consideration, even if little or no cash is paid.
• Assumption of debt is wider than formally signing the loan; it can include release of the transferor or an indemnity in their favour.
• Where property is jointly owned before or after the transfer, the debt assumed is generally matched to each person’s ownership share rather than automatically to the full debt.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Stamp Duty Land Tax: Debt Assumption and Release Guidelines Under FA03/SCH4/P

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