Readers’ forum: Correct date for claiming input tax

My question is simple: one of my clients purchased some machinery for £110 000 plus VAT and the invoice issued by the seller is very confusing because it records two separate dates:

• Time of supply – 29 June 2024
• Date of issue – 1 July 2024

As I understand it the supplier must account for output tax according to the time of supply ie by including it on their June 2024 return assuming they complete returns on a calendar quarter basis. However can my client claim input tax on their June return or not until the next one for the September quarter? My client does not use the cash accounting scheme. A colleague says that we must wait until September because the invoice was not held by the end of the June period so a claim would be premature and subject to a potential timing...