Dear Sirs .............

Date:

Account No.

Invoice No.

Amount Due.

Our records show that despite previous statements and demands the above amount still appears to be due.

If payment of this amount is not received within the next ....days this account will be passed to our Collection Agency ( name of................) for further action.

Please contact the writer on the above telephone number within the next (....) days, should there be a specific reason why this account remains unpaid.

Yours.........