If you've already paid a bill outside of QuickBooks, you don't have to enter
the bill in QuickBooks.
If you want QuickBooks to track all your bills for accounting purposes, however,
you can enter the bill anyway.
If you don't enter the bill in the Enter Bills window, you still
need to assign the payment to the appropriate expense account,
depending on how you paid the bill in the first place:
If you paid the bill with a credit card, record the payment in the
Enter Credit Card
If you paid the bill with a check, cash, or other form of payment,
record the payment in the
Write Checks window.
Ways to pay bills
Voiding or deleting a bill or payment