What Is the Accounts Payable Process?
The accounts payable process is the end-to-end sequence a business follows from the moment a supplier invoice arrives to the moment it is paid and reconciled. It is a control process as much as an administrative one: each step exists to confirm the business is paying the right supplier, the right amount, exactly once.
The Nine Steps in the Accounts Payable Process
- Invoice receipt.
The invoice arrives by email, mail, portal, or EDI and is logged so it cannot be lost. - Data capture.
Vendor, invoice number, dates, line items, tax, and totals are extracted. - Validation.
Details are checked against the vendor master file, tax rules, and pricing agreements. - Matching.
The invoice is compared to its purchase order and goods receipt note. - GL coding.
The cost is assigned to the correct account, cost center, and period. - Approval.
The invoice is routed to an authorized approver based on amount, department, or exception type. - ERP posting.
The validated invoice is entered as a payable against the correct supplier and period. - Payment.
The invoice is scheduled and paid according to terms, with remittance detail sent. - Reconciliation.
The payment is matched back to the invoice and against the bank statement.
The Accounts Payable Process Flow
Drawn as a flow, the process is mostly linear with two decision points that determine whether an invoice moves or stalls.
Invoice received leads to capture, then to the first decision: does it reference a purchase order? If yes, the flow goes to three-way matching against the PO and goods receipt note. If no, it routes directly to approval as a non-PO invoice.
Matching produces the second decision: does everything agree? If yes, the invoice proceeds to coding, posting, and payment. If no, it becomes an exception and diverts to investigation, then either returns to the main flow once resolved or exits as a disputed item or debit memo.
Every stall in a real AP function happens at one of those two decision points: a missing PO reference, or an unresolved mismatch.
A Single Invoice Through the Full Process
EXAMPLE
A $9,000 invoice arrives for 500 units at $18. Capture extracts the header and lines. Validation confirms the vendor and 2/10 net 30 terms. Matching compares it to PO #4471 and the goods receipt note, which shows 470 units received. The 30-unit variance is flagged as an exception and routed to the purchasing manager, who confirms a short shipment. A $540 deduction is documented, the invoice posts at $8,460, payment goes out on day 9 to capture the 2% discount, and the payment is reconciled to the invoice and bank feed.
Nine steps for one invoice. At 400 invoices a month, the process runs 3,600 times a year, and every step is a place where an invoice can stall.
Accounts Payable Best Practices
- Centralize intake
One destination for every invoice, so nothing lives in an individual inbox. - Enforce PO referencing
Require suppliers to quote a PO number, which is what makes matching possible at all. - Separate the four AP duties
Vendor maintenance, invoice entry, approval, and payment execution should not overlap. - Approve by exception
Route only mismatches and unusual items to a human rather than every invoice. - Standardize GL coding rules
So the same expense type is coded identically regardless of who handles it. - Verify vendor bank changes out of band
Confirm by phone to a known number, never by replying to the email requesting the change. - Reconcile continuously
Match payments to invoices as they clear instead of batching it into month-end. - Review supplier statements on a schedule
Proactively, rather than only when a supplier raises a discrepancy.
How to Improve the Accounts Payable Process
Improvement work is only measurable against a baseline, and four metrics cover most of what matters. Cost per invoice is the one that makes the case for change.
FORMULA
Cost Per Invoice = Total AP Operating Cost ÷ Number of Invoices Processed
- Cost per invoice: fully loaded processing cost including salaries, systems, and overhead.
- Invoice cycle time: days from receipt to posting, which is the number approval delays inflate.
- Exception rate: share of invoices requiring manual intervention rather than flowing through.
- Discount capture rate: share of available early payment discounts actually taken.
EXAMPLE
An AP function with three staff at a fully loaded $65,000 each, plus $18,000 in systems, costs $213,000 a year. Against 400 invoices a month, or 4,800 a year, that is roughly $44 per invoice. Cutting the exception rate from 35% to 10% removes most of the manual handling driving that number.
The highest-leverage changes are usually the two that reduce exceptions rather than the ones that speed up handling: enforcing PO references at the supplier level, and ensuring receiving records are entered on delivery rather than retroactively.
What Is an Automated Accounts Payable Process?
An automated AP process executes the same nine steps without manual data entry at each stage. Software or AI agents capture the invoice, validate it against vendor and pricing records, match it to the PO and receipt, apply coding rules, post to the ERP, and reconcile the payment. Humans handle exceptions and approvals rather than keying.
The distinction worth understanding is how far the automation reaches. Many tools automate capture and approval but stop before ERP posting, leaving the final entry manual. Others depend on an API connection to the accounting system, which excludes the legacy and desktop ERPs common in distribution and manufacturing.
Computer-use automation closes that gap by operating the ERP through its own interface the way a person does, which means systems with no API can still be automated end to end.
The AP Process in SAP, Oracle, and NetSuite
The nine steps are the same in every system; what differs is terminology and where the control points sit.
- SAP: invoice verification is the matching step, three-way match runs against the purchase order and goods receipt, and tolerance keys govern what passes automatically.
- Oracle: invoices route through validation and approval workflows, with holds applied automatically when a match fails.
- NetSuite: vendor bills match against purchase orders and item receipts, with approval routing configured per subsidiary or amount.
- Legacy and desktop ERPs: the same logic often exists but without an API, so integration has to work through the user interface.
Frequently Asked Questions About Accounts Payable Process
1. What is the accounts payable process?
The accounts payable process is the end-to-end sequence from receiving a supplier invoice through paying and reconciling it, including capture, validation, matching, coding, approval, ERP posting, payment, and reconciliation.
2. What are the steps in the accounts payable process?
Nine steps: invoice receipt, data capture, validation against vendor and pricing records, matching to the purchase order and goods receipt note, GL coding, approval routing, ERP posting, payment with remittance detail, and reconciliation against the bank statement.
3. What does the accounts payable process flow look like?
Invoice received leads to capture, then a decision on whether it references a purchase order. PO invoices go to three-way matching; non-PO invoices route straight to approval. Matching creates a second decision: matched invoices proceed to coding, posting, and payment, while mismatches divert to exception handling.
4. What are accounts payable best practices?
Centralize invoice intake, enforce PO referencing with suppliers, separate vendor maintenance from invoice entry, approval, and payment execution, approve by exception rather than reviewing everything, standardize GL coding, verify vendor bank changes by phone, and reconcile continuously.
5. How do you improve the accounts payable process?
Measure cost per invoice, cycle time, exception rate, and discount capture first. The highest-leverage changes reduce exceptions rather than speeding up handling: enforcing PO references at the supplier level and entering receiving records on delivery instead of retroactively.
6. What is an automated accounts payable process?
An automated AP process executes the same nine steps without manual data entry, using software or AI agents to capture, validate, match, code, post, and reconcile. Humans handle exceptions and approvals. Coverage varies: some tools stop before ERP posting, and most require an API to the accounting system.
7. How does the accounts payable process work in SAP or NetSuite?
The steps are identical, only the terminology differs. SAP calls the matching step invoice verification and uses tolerance keys to govern automatic passes. NetSuite matches vendor bills against purchase orders and item receipts. Legacy desktop ERPs follow the same logic but often have no API.
