Every invoice must contain certain items in order to comply with VAT regulations.

Every sales invoice must include the following items in order to comply with the VAT regulations:

1. Your company’s name and address
2. Your client’s name and address
3. The date
4. The invoice number
5. A description of the supply (i.e. work being done)
6. The net amount due
7. The rate and amount of VAT
8. The gross amount due
9. Your company’s own VAT number (preceded by GB)

You should print the VAT number using the conventional spacing after the third and seventh digits. For the invoice number, you may use any combination of numbers that distinguishes one invoice from another. There is no particular benefit in pretending that you have already issued a thousand invoices by starting from 1001, but the invoice numbering system should be sequential.