Liane wrote this article awhile ago:
A few versions ago, Microsoft added a little checkbox to the the Account Maintenance window in Dynamics GP called “Allow Account Entry”. Even though this checkbox has been around for a while, I’ve found that many Dynamics GP users do not know what it is for and how to make use of it.
If this checkbox is marked, users can manually select/enter the account on any transaction in Dynamics GP. If this checkbox is NOT marked, users CANNOT enter/select the account on any transaction throughout Dynamics GP; the account can only be used on a default basis.
Therefore, you can use this feature to prevent users from entering accounts that never should be manually updated. By default, the checkbox is marked. I recommend that the box be unmarked for Accounts Payable, Account Receivable, Accrued Purchases accounts and possibly inventory.
If you’ve ever had the unfortunate experience of spending hours reconciling a General Ledger control account to the corresponding subsidiary and finding that the difference in the balances was due to transactions on which the control account was manually entered, you will welcome the opportunity to stop users from entering such transactions. If there is an unusual circumstance in which the subsidiary is right and the GL is wrong, you can temporarily mark the checkbox, enter/post the correcting entry, then unmark the checkbox.