Offer your thoughts or opinion on the input financial query or topic using your financial background.

incorrect printed information on check stock
Probably a bad assumption, but I'm assuming your in the United States. Keep in mind, that the check number is printed in 2 places on the front of each check. First, in the upper right corner, and also along the bottom edge on of the check. Since the check number is scanned by the bank from the bottom edge of the check, covering or otherwise modifying the check number on the upper left corner will have no effect on the check number that is recorded when the check is processed. And, you can't modify or cover the numbers or place any marks in the area of the numbers along the bottom of the check as this will likely interfere with processing of checks. So, modifying the check numbers will not work. Your choices are basically to:   The check numbers are not used in any way in clearing the check, the numbers are only for your convenience, so processing checks with duplicate numbers won't matter.  The check numbers are recorded when processed at your bank so they can be shown on your printed and online statements. The only time the check number might be important is if you had to "stop payment" on a particular check, or otherwise inquire about a particular check. But this should not really be an issue because by the time you have used up the first batch of checks, and start using the checks with duplicate numbers, the first use of the early duplicate numbered checks will be sufficiently long ago that there should not be any chance of processing checks with duplicate numbers at the same time. You didn't mention how many checks you have with duplicate numbers, or how frequently you actually write checks so that may play a part in your decision. In my case, 100 checks will last me literally years, so it wouldn't be a problem for me.