In using the Accounts Payable application, you need to understand the difference between a posted A/P transaction and an unposted A/P transaction. The following example illustrates this distinction.
Let's say you receive an invoice from a vendor, and you enter it into the New A/P Transactions window and click Add. As soon as you have done so, it becomes an unposted transaction. While the transaction is unposted, you can make any changes to it or even delete it, if necessary.
Once you are satisfied that the transaction is entered properly, you then post the transaction by running the Post Transactions To A/P Files report. As a result, the transaction is sent from the New A/P Transaction window to the Open Item file, where it resides with other posted transactions. You must post A/P transactions in order to pay them.
Once posted, A/P transactions can no longer be accessed through the New A/P Transactions window. However, they can be viewed in the View Posted A/P Transactions window.
Posted transactions cannot be deleted directly. Instead, an off-setting transaction must be created to delete posted transactions. For example, let's say you posted an invoice for $50.00, but later discover you did so in error. Since you cannot delete the transaction (because it's already been posted), you would create a "cancellation voucher" to offset the original transaction. Lastly, the off-setting transaction (in this case, a cancellation voucher) must itself be posted by running the Post Transactions To A/P Files report.
If you need to change a posted transaction, you can change the following fields: Remit-To Vendor, Due Date, Discount Date, Discount Amount, or Reference Amount. You do so in the Selecting, Paying, and Adjusting Invoices window (not in the New A/P Invoices window). To change any other fields, you must create a cancellation voucher to back out the original transaction and then re-enter the transaction correctly. However, if you need to change the distributions to General Ledger, you must create an adjustment voucher.