User Invoice Email: The email address where the invoice will be sent. This is typically the client’s preferred email for billing communication.

Contract Reference: A unique identifier linking the invoice to the specific contract it pertains to, allowing easy tracking of the associated agreement.

Vendor Contract Reference: The vendor's internal reference number for the contract, used to match the invoice with the service provider’s records.

EDI Number: An Electronic Data Interchange (EDI) number, if applicable, used for seamless automated exchange of invoice information between the vendor and client.