If you use the Accounts Payable function in QuickBooks, it is important to make sure the bills are marked paid in the system.  There are several reasons you may have open but paid bills.  You may have cut a manual check, paid with cash or ACH or used a credit or debit card to pay the bill. If you are not cutting the check against the bill, the bill will need to be paid manually, to close out the open A/P. This will be important for monthly reconciliations.

If you use bank feeds, this will need to be completed before you approve your transactions.  This will allow QuickBooks to match the transactions and avoid duplication.

Go to Vendor > Pay Bills

For the manual check, cash, ACH or Debit Card transactions, in the pay bills window, select the bill to be paid as you would to print the check, enter the day it was paid, choose the Method- Check then choose Assign check number, and then in the Account dropdown window choose the appropriate account. Then hit the Pay Selected Bills button.

In the pop-up window choose Let me assign check numbers below, enter the manual check number and in the case of Cash, Debit or ACH payment you can leave it blank or type ACH or Debit.

For credit card payment enter the date it was paid, choose the Method- Credit Card then choose the appropriate credit card in the Account dropdown window. Then hit the Pay Selected Bills button and these bills will be removed from your A/P.