Dear :

We are sorry that we cannot process your invoice No. for [goods] because this invoice represents only part of the purchase listed in our order No. . We cannot pay until the entire order has been filled.

We have changed our policy because we have had problems with suppliers whose invoices for part of the order often led to confusion.

We hope you will understand our position, and we would appreciate a new invoice from you when the entire order has been filled.

Sincerely yours,

[name]

[title]