Accounts Payable: Managing What You Owe
Accounts Payable is the discipline of paying what your company owes — accurately, on time, and without paying twice. Done well, it protects vendor relationships, captures early-payment discounts, and keeps cash from walking out the door for things that were never actually delivered. Done poorly, it invites duplicate payments, missed discounts, and vendors who stop extending credit. This lesson covers the full AP cycle from invoice intake through payment.
Why this skill matters professionally
AP clerks and staff bookkeepers are hired specifically for this skill — it's one of the most common entry points into a bookkeeping career. Employers care because AP touches cash directly: a sloppy AP process bleeds money through duplicate payments, missed discounts, and late fees, while a tight one can meaningfully improve a company's cash position. Good AP practice is also a control function. The three-way match (invoice, purchase order, receiving report) exists specifically to prevent paying for goods that were never ordered or never received — a classic fraud and error vector that hiring managers explicitly test for in interviews.
Learning objectives
- Explain the three-way match.
- Age payables and prioritize payments.
Background concepts
What accounts payable represents
AP is a liability account — money your company owes to vendors for goods or services already received but not yet paid for. It sits on the balance sheet until payment clears, at which point it's removed and cash decreases.
The AP cycle
Purchase order → goods/services received → vendor invoice arrives → invoice is matched and approved → payment is scheduled and made.
- Purchase order (PO): what you agreed to buy, at what price.
- Receiving report: confirmation that the goods actually arrived (or the service was performed).
- Vendor invoice: the vendor's bill, which should match the PO and receiving report.
The three-way match
Before any invoice is paid, compare the invoice, the PO, and the receiving report. Quantities, prices, and vendor details must agree across all three documents. This is the single most important internal control in AP.
Terms and discounts
Vendor terms like 'Net 30' mean payment is due 30 days after the invoice date. A term like '2/10 Net 30' means a 2% discount is available if paid within 10 days, otherwise the full amount is due in 30. Capturing a 2% discount for paying 20 days early is a very high effective annual return — worth prioritizing when cash allows.
Step-by-step
1. 1. Invoice intake
When an invoice arrives (mail, email, or vendor portal), log it immediately with vendor name, invoice number, invoice date, due date, PO number, and amount. Route it for the three-way match before it goes anywhere near payment.
2. 2. Three-way match
Pull the original PO and the receiving report. Confirm the vendor, item descriptions, quantities, and unit prices all agree. If everything matches, approve for payment.
PO #4501: 200 units @ $12.50 = $2,500.00 Receiving report: 200 units received, condition OK Vendor invoice #INV-9981: 200 units @ $12.50 = $2,500.00 Match confirmed → approve for payment
3. 3. Handle mismatches
If quantities or prices don't agree, hold the invoice and route it back to purchasing or the receiving department for resolution. Never pay a mismatched invoice hoping to sort it out later — it's much harder to recover an overpayment than to withhold one.
4. 4. Code the invoice to the right account
Every invoice needs a GL (general ledger) account and, if used, a department or job code. A $2,500 inventory purchase and a $2,500 office-supply purchase look identical on a check but land in very different places on the income statement.
Dr Inventory 2,500.00
Cr Accounts Payable 2,500.005. 5. Approval workflow
Most companies require sign-off above a dollar threshold — e.g., a manager approves anything over $500, and the owner or controller approves anything over $5,000. This is a control against unauthorized spending, not just a formality.
6. 6. Age your payables
Run an AP aging report weekly, bucketing invoices by how overdue (or not) they are.
Vendor Current 1-30 31-60 61-90 90+ Acme Supply 1,200 0 0 0 0 Metro Freight 0 850 0 0 0 Bright Print 0 0 400 0 0 Total 1,200 850 400 0 0
7. 7. Prioritize the payment run
Pay invoices with early-payment discounts first if cash allows, then anything due within the next 7-10 days, then the oldest outstanding balances to protect vendor relationships and credit terms.
8. 8. Cut the payment and record it
Whether by check or ACH, record the payment against the specific invoice(s) it settles, not just against the vendor generally — this keeps the vendor's open-item ledger accurate.
Paying the $2,500 invoice above:
Dr Accounts Payable 2,500.00
Cr Cash 2,500.009. 9. File and reconcile the AP subledger
The total of all open vendor invoices (the AP subledger) should always equal the Accounts Payable balance on the general ledger. Reconcile this monthly, the same way you reconcile a bank account.
Real-world workplace examples
Capturing a 2/10 net 30 discount
A $10,000 invoice with 2/10 net 30 terms saves $200 if paid within 10 days instead of 30. Paying 20 days early for a 2% discount is roughly equivalent to a 36% annualized return — almost always worth prioritizing if the business has the cash.
Invoice: $10,000, terms 2/10 net 30
Paid within 10 days:
Dr Accounts Payable 10,000.00
Cr Cash 9,800.00
Cr Purchase Discounts 200.00Duplicate invoice caught before payment
A vendor accidentally emails the same invoice twice, a week apart, with slightly different formatting. AP intake catches it because the invoice number is identical, preventing a duplicate payment.
Mismatched receiving report
A vendor bills for 500 units but the receiving report shows only 480 arrived. AP holds the invoice and asks the vendor for a credit memo for the 20 missing units before releasing payment.
Rush payment for a critical vendor
A key raw-material supplier threatens to hold the next shipment over one overdue invoice. AP flags it for same-day ACH payment outside the normal weekly run to avoid a production shutdown.
Recurring subscription invoices
Software and utility vendors often bill automatically each month. AP still verifies the amount against the contract each cycle, since price increases sometimes slip through unnoticed on auto-pay.
Practical scenarios
Case: Cash-strapped month, which invoices get paid?
Bright Manufacturing has $18,000 available for this week's payment run but $31,000 in approved invoices due. The AP aging shows: Vendor A, $2,000 with 2/10 net 30 terms, discount deadline is tomorrow. Vendor B, $9,000, 45 days past due, has already sent a second notice. Vendor C, $20,000, due in 12 days, no discount, strong ongoing relationship. Decision: Pay Vendor A first ($1,960 after discount) to capture the $40 savings before the deadline expires — small dollar amount but a guaranteed return. Pay Vendor B next ($9,000) since it's already significantly overdue and risks a credit hold or collections action. That's $10,960 spent, leaving $7,040 toward Vendor C's $20,000, which isn't due for another 12 days — call Vendor C proactively to explain a partial payment now with the remainder next week, preserving trust rather than going silent.
Case: implementing the three-way match at a growing company
A 15-person company that used to just pay whatever invoices arrived is scaling and starts losing money to billing errors. The bookkeeper introduces POs for any purchase over $200, requires receiving confirmation from whoever accepts the delivery, and holds all invoices until both documents are on file. Within two months, three billing discrepancies are caught before payment (a freight overcharge, a pricing error, and a partial shipment billed as complete), together saving over $1,800 — more than paying for the extra administrative time.
Common mistakes beginners make
Paying from a statement instead of an invoice
Vendor statements summarize account activity but can include errors or double-counted amounts. Always pay against the original invoice and its matching documents, not a statement balance.
Skipping the three-way match under time pressure
When invoices pile up, it's tempting to just pay and sort out details later. This is exactly when overpayments and fraud slip through — the match takes minutes but prevents costly errors.
Missing early-payment discounts
Discount terms are easy to overlook if invoices aren't flagged the moment they're entered. Set a reminder tied to the discount deadline, not just the final due date.
Letting one person control the entire AP cycle
If the same person can create a vendor, approve an invoice, and issue payment, there's no check against a fake vendor or self-dealing. Separate these duties even in a small office.
Coding everything to a generic 'expenses' account
Vague coding makes the income statement useless for decision-making. Take the extra 30 seconds to code each invoice to the correct GL account.
Best practices
- Require a three-way match before any invoice is paid.
- Log every invoice the day it arrives, even if payment is weeks away.
- Run an AP aging report weekly, not just at month-end.
- Separate the duties of invoice approval, vendor setup, and payment issuance.
- Track and prioritize early-payment discounts explicitly.
- Pay against specific invoices, never a vague vendor balance.
- Reconcile the AP subledger to the general ledger monthly.
- Set a dollar-threshold approval hierarchy and enforce it consistently.
Professional tips
- Set up a dedicated AP inbox so invoices never get buried in someone's personal email.
- Flag discount terms immediately on intake so they're never discovered after the deadline.
- Watch for new 'vendors' with a P.O. box and no phone number — a classic sign of invoice fraud.
- Batch payments weekly rather than as invoices arrive; it's easier to review and control.
- Keep a vendor master file with W-9s and banking details locked down — vendor detail changes are a common fraud vector.
- When a vendor calls about a 'missing' payment, verify against your own records before resending — it might already be in transit.
Practice exercises
Perform a three-way match
PO #7702 calls for 50 units at $40 each. The receiving report confirms 50 units received. The invoice bills for 52 units at $40 each. What do you do, and what journal entry (if any) do you post?
Answer: Hold the invoice — quantity mismatch (52 billed vs 50 received/ordered). No entry until resolved. Request a corrected invoice or credit for 2 units ($80).
Calculate an early-payment discount
An $8,400 invoice has terms 1/15 net 45. If paid on day 15, how much cash is remitted, and what's the journal entry?
Answer: Discount = $84. Cash paid = $8,316. Dr AP 8,400 / Cr Cash 8,316 / Cr Purchase Discounts 84.
Build an aging report
Given 6 vendor invoices with dates and amounts, bucket them into Current, 1-30, 31-60, 61-90, and 90+ days past due as of a given date.
Review questions
What is the three-way match and why does it matter?
Comparing the invoice, purchase order, and receiving report before payment; it prevents paying for goods never ordered or never received.
What does '2/10 net 30' mean?
A 2% discount applies if paid within 10 days; otherwise the full invoice is due in 30 days.
Why should invoice approval, vendor setup, and payment issuance be separated among different people?
It prevents any single person from creating a fake vendor and approving/paying fraudulent invoices without detection.
Why pay against specific invoices rather than a vendor's overall statement balance?
Statements can contain errors or duplicated charges; paying against the original invoice keeps the vendor's open-item ledger accurate.
What should you do when an invoice doesn't match its PO or receiving report?
Hold the invoice and route it back to purchasing or receiving for resolution rather than paying and sorting it out later.
Key takeaways
- AP is a liability representing goods/services received but not yet paid for.
- The three-way match is the core control that prevents overpayment and fraud.
- Terms like 2/10 net 30 offer valuable discounts for early payment.
- Aging reports drive smart, prioritized payment decisions.
- Duty separation between approval, vendor setup, and payment is essential.
- The AP subledger should always tie to the general ledger balance.
- Vague GL coding undermines the usefulness of financial statements.
Frequently asked questions
What's the difference between AP and accrued expenses?
AP typically involves an actual vendor invoice already received; accrued expenses are costs incurred but not yet invoiced, estimated at period-end.
Should small businesses bother with purchase orders?
Yes for anything beyond trivial purchases — POs create the paper trail the three-way match depends on, even in a two-person shop.
How often should AP aging be reviewed?
Weekly at minimum; daily in cash-tight businesses.
What happens if a vendor invoice is paid twice by mistake?
Contact the vendor immediately to request a refund or apply the overpayment as a credit against the next invoice.
Is it okay to pay early even without a discount?
It can hurt cash flow unnecessarily; usually better to pay right around the due date unless a discount or vendor relationship reason justifies paying early.
How long should AP records be kept?
Retention periods vary by jurisdiction, but many businesses keep vendor invoices and payment records for at least several years for audit and tax purposes.
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