GL Accounts cannot be deleted from the system when they are used on a transaction or budget. However, if you are trying to delete a GL Account but are still receiving this error message, it can be due to the fact that the account is listed on a Memorized Transaction, such as a Journal Entry or AP Invoice.
Review your Memorized Transactions and remove any GL Accounts that should be deleted. When all are updated, return back to the GL Account record and delete it.