Dear Mr. Smith,
We wish to inform you that our check book containing 10 blank checks is missing. We discovered this yesterday after we had moved the furniture etc. in the office and threw out some unwanted things. We do not know whether the checks were merely misplaced or were thrown out with the rubbish. We are still looking for them. The checks are numbered from 12345 to 12354.
Meanwhile please do not make any payment for any of the above checks if or when they are presented to you.
We would appreciate it if you could issue a new check book to us as soon as possible.