VATREC16042 | Other Invoicing arrangements for particular businesses: Retailers: Less detailed VAT invoices
From HM Revenue & Customs · VAT Traders’ Records Manual
A less detailed VAT invoice may be issued where:
the value of the supply, including tax, is £250 or less;
if the registered person is based in Northern Ireland, the supply is not to a person from another EU member state.
the invoice does not include any exempt supplies.
A less detailed VAT invoice need contain only the following particulars:
the name, address and registration number of the retailer;
the time of the supply;
a description sufficient to identify the goods or services supplied;
the total amount payable including VAT;
for each rate of VAT chargeable, the gross amount payable including VAT; and
the VAT rate applicable.
Paragraph 16.6.2 of VAT guide (VAT Notice 700) - GOV.UK provides a useful summary here.