Guide to Completing the Additional Dwelling Supplement Section on Tax Returns

Completing the Additional Dwelling Supplement section of an LBTT return

The ADS section of an online LBTT return is used to work out what part of the purchase price is actually subject to the Additional Dwelling Supplement and, where relevant, what part relates to a replacement main residence. It is a form-filling guide rather than a full statement of the law, so mixed-use and multi-property purchases may need a just and reasonable apportionment of the price.

• The ADS section only appears if you have already answered “yes” to the earlier question asking whether ADS applies.
• You must enter the total consideration liable to ADS, which may be less than the full purchase price.
• If the transaction includes more than one property, or both residential and non-residential property, the price should be apportioned on a just and reasonable basis to the dwellings chargeable to ADS.
• If the buyer is replacing their main residence, the return asks separately for the amount attributable to the new main residence.
• For a single dwelling that is the replacement main residence, that figure will usually be the same as the total consideration for the transaction.
• If the buyer intends to sell their former main residence within 18 months, the return also asks for the address of the new main residence.

Scroll down for the full analysis.

How to complete the Additional Dwelling Supplement section of an LBTT return

This page explains what the Additional Dwelling Supplement, or ADS, section of an online LBTT return is asking for. The source material is about completing the return, not the full legal test for whether ADS is due. The practical point is that you must identify which part of the price is actually chargeable to ADS, and whether any part of the purchase relates to replacing the buyer’s main residence.

What this rule is about

ADS is an extra charge that can apply when a buyer acquires an additional dwelling in Scotland. In some cases, a transaction may include more than one property, or may include both residential and non-residential property. In those situations, the whole purchase price is not always the amount on which ADS is calculated.

The return therefore asks questions designed to separate out:

• the consideration that is chargeable to ADS, and
• if relevant, the part of the transaction that relates to a replacement main residence.

The source also shows that the online return only opens the ADS section if the filer has already answered “yes” to the earlier question asking whether ADS applies to the property.

What the official source says

According to Revenue Scotland’s return-completion guidance:

• the ADS section appears only if “yes” has been selected to the question “Does ADS apply to this property?” in the “About the property” section;
• the return asks whether the buyer is replacing their main residence;
• the return asks for the “total consideration liable to ADS”;
• if the transaction covers more than one property and not all of them are chargeable to ADS, the amount entered should be the part of the total consideration attributed, on a just and reasonable basis, to the properties that are chargeable to ADS;
• if the transaction is a non-residential transaction that includes the purchase of one or more dwellings, the figure entered should be the amount of the price attributed, on a just and reasonable basis, to the dwelling or dwellings only, because ADS is due only in respect of the additional dwelling element;
• if the buyer is replacing their main residence, the return asks for the “amount of ADS liability from new main residence”;
• for a single dwelling that is the replacement of the main residence, that figure will be the same as the total consideration for the transaction;
• if the transaction includes both a replacement main residence and other property, including other dwellings, the figure should be the consideration attributable to the replacement main residence; and
• if the buyer intends to sell their main residence within 18 months, the return asks for the address of the new main residence.

The source also points readers to separate ADS legislative guidance for the full legal rules.

What this means in practice

The return is not simply asking for the total purchase price in every case. It is asking you to identify which part of the consideration relates to dwellings that are actually within ADS.

That matters because mixed or multiple-property transactions can produce different figures for:

• the total transaction consideration for LBTT generally,
• the amount on which ADS is calculated, and
• the amount attributable to a replacement main residence.

For example, if a buyer acquires a shop with a flat above it and the transaction is treated as non-residential for LBTT purposes, ADS may still need to be considered for the dwelling element. In that case, the figure for ADS is not the full mixed-use price. It is the part of the price that can just and reasonably be attributed to the dwelling or dwellings.

Similarly, if one transaction includes a new home for the buyer and another dwelling as well, the return requires a separate figure for the part relating to the replacement main residence. That is relevant because the replacement of a main residence has special significance within the ADS rules, including in cases where a previous main residence is intended to be sold within 18 months.

How to analyse it

A sensible way to approach this section of the return is to work through the following questions.

• Has the filer already concluded that ADS applies? If not, the ADS section should not be completed. The source assumes that this decision has already been made in the earlier part of the return.
• Is the buyer replacing their main residence? The return branches depending on the answer.
• What property is included in the transaction? Is it a single dwelling, multiple dwellings, or a transaction that includes non-residential property as well?
• Which part of the consideration is actually attributable to the dwellings that are chargeable to ADS?
• If not all properties in the transaction are chargeable to ADS, what is a just and reasonable apportionment of the consideration?
• If a replacement main residence is involved, what part of the consideration is attributable to that replacement residence?
• Does the buyer intend to sell their former main residence within 18 months? If yes, the return asks for the address of the new main residence.

The phrase “just and reasonable basis” is important. It means the apportionment should reflect the facts and should not be arbitrary. The source does not prescribe a single method. The correct approach will depend on the nature of the properties and the transaction.

Example

Illustration: a buyer purchases two properties in one transaction in Scotland. One is the buyer’s new home. The other is a separate flat that will be retained as an additional dwelling. The total price is a single combined amount.

If ADS applies, the return will ask whether the buyer is replacing their main residence. If the answer is yes, the return will require:

• the total consideration liable to ADS, being the amount attributable to the dwellings chargeable to ADS, and
• the amount attributable to the replacement main residence.

If the combined price covers both properties together, those figures may need to be apportioned on a just and reasonable basis. The source makes clear that the relevant figure is not automatically the full purchase price for every ADS field.

Why this can be difficult in practice

The hard part is often not filling in the boxes, but deciding what numbers properly belong in them.

Several issues can make this fact-sensitive:

• A single transaction may include different types of property, but ADS applies only to the dwelling element.
• Not every dwelling in a transaction is necessarily chargeable to ADS in the same way.
• Where there is one global price, the filer must decide how to apportion it on a just and reasonable basis.
• The question whether a buyer is replacing a main residence can depend on wider ADS rules that are not set out in this short return-completion page.
• The question about intending to sell a main residence within 18 months points to rules that may affect how the transaction is treated, but the source here does not explain those rules in full.

So, while the form guidance tells you what to enter, it does not by itself resolve all legal questions about whether ADS is due or how the replacement of a main residence should be analysed. Those points need to be checked against the legislative guidance referred to in the source.

Key takeaways

• The ADS section of the online LBTT return appears only if “yes” has already been selected to the question asking whether ADS applies.
• The figure for ADS is not always the full purchase price; in mixed or multiple-property transactions, it may need to be apportioned on a just and reasonable basis.
• If the buyer is replacing their main residence, the return asks separately for the amount attributable to that replacement residence and whether the former main residence is intended to be sold within 18 months.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Guide to Completing the Additional Dwelling Supplement Section on Tax Returns

View all LBTT Guidance Pages Here