• Higher Rates Increase: From 31 October 2024, the higher rates for additional dwellings increased to 5 percent above the standard residential rates of SDLT.

• Contracts: Before 31 October 2024: If a contract was entered into on or before 30 October 2024 but completes after that date, the higher rates will apply at the pre-31 October 2024 rate of 3 percent above the standard rates, unless certain conditions apply.

• Substantial Performance: Before 31 October 2024: If a contract was substantially performed before 31 October 2024 but completes after that date, no additional tax is chargeable if the increase in rates is the only reason for additional tax.

• Substantial Performance: Between 31 October 2024 and 31 March 2025: If a contract is substantially performed between these dates but completes after 1 April 2025, no additional tax is chargeable if the increase in rates is the only reason for additional tax.

Substantial performance of a property contract means that either the whole or substantially the whole of the price is paid or the purchaser occupies the whole or substantially the whole of the property.

For example:

• A property is priced at £300,000;
• If the property is taken possession of or used as intended;
• or a significant amount of the purchase price has been paid (typically 90%)

then the contract is considered as substantially performed.