(For credit card, asset, and liability accounts, this field is Ref.)
The number of the transaction. If you are entering a new check, QuickBooks increments the number for you automatically. For example, if your last check was #345, the new check will be #346.
When the words “To print” appear in place of a check number, it means that the check is marked as “to be printed” in the Write Checks window. When you print the check, QuickBooks replaces “To print” with the check number. By scrolling the register, you can see which checks you've printed.
If you are entering a check directly in the register, you'll have to enter “To print” over the check number if you want QuickBooks to track whether you've printed the check. Don't worry about deleting the number; it will reappear when you print the check.