As mentioned earlier – the standard rate of VAT will be temporarily cut from 23% to 21% from September 1st 2020 until the end of February 2021.
In general, goods and services supplied before 1 September 2020 will be liable to VAT at the rate at the time of supply, namely 23%.
However, where goods and services are supplied in August 2020 by a trader who is obliged to issue a VAT invoice, and that trader issues the invoice after 31 August 2020, the rate in place in September applies, namely 21%.
Credit or Debit Notes :
Any VAT credit note or debit note relating to a supply of goods or services, which contains a VAT adjustment, should show VAT at the rate in place at the time the original invoice was issued. For example, if goods are supplied in August 2020 and a credit note is issued in September 2020 (due perhaps to an adjustment in the price of the goods or services), the rate of VAT on that credit note is 23%. This is because the goods or services were supplied when the rate of VAT was 23%.