If you still have the member standing in front of you still you can ask them for the check back, then use Tool #31 Reverse Tran/Adjust Drawer (Same Day) to void the check. (Remember this tool will correct the member, GL and tellers.)

If the member has already left with the check and you notice that you forgot to hit post you will need to post the transaction correctly. Then have accounting void the new check that prints out, making sure that the check the member left with is still showing outstanding in the check register.

NOTE: This situation is not likely to happen when using Xpress Teller, since posting and printing a check occurs as part of the same step.