Answer
The tax point is the date a supply is treated as taking place for VAT, determining which VAT period and rate apply. The basic tax point is when goods are removed or services performed, but an earlier invoice or payment can create an actual tax point. It matters for placing VAT in the correct return period.
Invoice issued 28 Mar for goods delivered 2 Apr -> tax point 28 Mar (invoice date).Real-world example An invoice raised before delivery sets an earlier tax point, pulling the VAT into the prior period.