• No matter how subledger files are arranged, the ACCOUNTS PAYABLE subledger summary must neatly organize, categorize, and summarize all accounts for posting to the ACCOUNTS PAYABLE line of the general ledger. The most common method in manual systems is a column-ruled sheet of paper that lists the following information for summarization:
• Date. When the purchase was made or the debt incurred.
• Vendor. To whom the money is owed.
• Purchase description. What was purchased or how the debt was incurred.
• Amount. How much money is owed.
• Expense or assets accounts. The general ledger accounts to which the purchase or debt is posted.
• Cash. Whether or not this was a cash transaction.
• Accounts payable. Whether or not this was a credit transaction to be posted to this account.

In addition to serving as a transaction summary, this A/1′ subledger summary page also is a source document for posting to the general ledger, which is generally done monthly.

Most accounts payable systems link with inven¬tory control. That way, when a shipment of materials arrives and is logged in, the warehouse entry appears immediately on the ACCOUNTS PAYABLE subledger and general ledger from which payment to that particular vendor is to be made. Again, double entries—and the occasional resulting errors—are avoided.