Accounts payable (AP) automation is software that pays a company's supplier bills. It reads each supplier invoice, checks it against the order and the delivery, schedules the payment and records it. A person approves only the exceptions. Accounts payable is also the name of the team that pays the bills.
Before this software, AP was a department of people. Employees typed each invoice into the accounting system by hand. They matched it to the purchase order, the document in which the company ordered the goods. They also matched it to the goods receipt note (GRN), the record that the goods actually arrived. This check of three documents is called a three-way match.
Imagine a chain of 12 hospitals in Thiruvananthapuram. It orders 500 boxes of surgical gloves from a supplier, at ₹620 a box, for ₹3,10,000. The order is raised in its procure-to-pay software. The goods arrive, and the store records 480 boxes received. The supplier's invoice arrives by email, for all 500 boxes. The AP software reads the PDF with an AI model. It finds the supplier, the GST number, the items and the amount. It then compares the invoice with the order and the GRN. The quantities do not match: 500 billed, 480 received. So it holds the invoice and asks an employee in the AP team to check. This part of the software is the invoice audit.
The employee confirms that 20 boxes are missing. The supplier sends a corrected invoice for 480 boxes, ₹2,97,600. Now all three documents match. The software schedules the payment for the due date. It sends the money through payouts, or pays with a one-time virtual card. Finally, it records the payment in the ERP, the hospital chain's main accounting system.
The software drafts and a person approves. This way of working is called human in the loop. The model does the reading and the matching. The employee handles only the invoices that do not match.
In India, timing also matters. Under India's income tax law, a buyer that pays a micro or small enterprise late can deduct that expense only in the year in which it actually pays. Late means after the date agreed in writing, which can be at most 45 days, or after 15 days if there is no written agreement. This rule was Section 43B(h) of the Income Tax Act, 1961. Since 1 April 2026, it is Section 37(2)(g) of the Income-tax Act, 2025. So AP software tracks the due date of each such invoice. In some countries, companies also pay suppliers through a supplier payment network that both sides join, instead of by cheque.