Hi Janice
You enter them the same way as if the year was not closed.
"Closing" your AP and AR really just resets the batch numbers back to 1, moves paid transactions to history, and zeroes out some statistics. What really matters is closing your Ledger, and that involves two steps: 1) giving your closing trial balance to your outside accountant, and 2) receiving and entering your accountant's adjusting entries.
Until the first step, you can continue working in the old year as usual. After the first step you should not allow activity to post to the old year other than what your accountant gives you. Also, at this point you would print out the final AP Open Payables and AR Aged Trial Balance reports whose totals agree to the Ledger trial balance. Any AP or AR activity that is retrieved with old year dates should be posted to the new year.
After the second step, you should officially close the Ledger.
Steve