How to set up a self-invoicing agreement between a VAT registered customer and his supplier and the conditions that must be met. Self-invoicing naturally gives more responsibility to the customer – it is the only one who can establish and establish a self-statement. Whether you are a customer or a supplier, both parties must agree to the terms of the agreement. In addition to the details of a full VAT invoice, a self-invoicing invoice to a supplier also includes: See also: Self-invoicing – Collection of self-invoiced invoices excluding VAT You must make invoices for all transactions with the supplier mentioned on the document for a period of up to twelve months (or the duration of the contract). .