A Request for Documentation of Invoice is an official request from a customer or client for an invoice to be issued for goods or services that have been received. This request is used to verify the transaction and provide proof of payment. It can also be used to verify the accuracy of the invoice amount and confirm that all the necessary information is included. There are two types of Request for Documentation of Invoice: 1. Pre-Invoice Request: This type of request is made before an invoice is issued, and is used to confirm the details of the transaction, the amount to be invoiced, and the payment terms. 2. Post-Invoice Request: This type of request is made after an invoice has been issued and is used to verify the details of the transaction, the amount invoiced, and the payment terms. It is also used to confirm receipt of payment and ensure that all the necessary information is included on the invoice.