WILL REMIT WHEN WORK IS COMPLETE
I am in receipt of your invoice #[INVOICE NUMBER], dated [DATE, ex. June 8, 1998].
Since [STATE WHAT STILL NEEDS TO BE DONE, ex. Units 5, 6 and 12 of our construction site still require clean up and disposal], I am unable to pay you at the moment. I will be pleased, however, to send you a check in the amount of $[AMOUNT] once the above work which we agreed upon is completed.