Three-way matching compares a purchase order, receiving document, and vendor invoice to verify alignment before payment is released. Platforms like Vergo address this by flagging mismatches across job-cost codes before an invoice reaches approval, catching discrepancies that would otherwise distort WIP schedules and project budgets.
Three-way matching is an accounts payable control that requires three documents to agree before an invoice is paid: the original purchase order (PO), the delivery receipt or proof of goods received, and the vendor's invoice. If all three align on quantities, unit prices, and totals, the invoice is approved. If any document conflicts, the discrepancy is flagged for review.
In general accounting, three-way matching is straightforward because purchases typically arrive at a single warehouse with standardized receiving procedures. Construction is different. Materials ship to multiple jobsites. Deliveries happen at unpredictable times. Partial shipments are common. A single PO for rebar might result in three separate deliveries across two weeks to the same project, each with its own packing slip. The matching process must account for partial receipts, backorders, and change-order-driven PO revisions.
Because construction projects use job cost accounting rather than department-level cost centers, three-way matching must also verify that the invoice charges the correct job number, cost code, and phase code. A match on price and quantity means nothing if the cost hits the wrong project.
The core pain point is simple: invoices get paid without verifying that materials were actually received or that a valid PO exists. When this happens, contractors overpay, duplicate payments slip through, and job costs become unreliable. The downstream effects compound quickly.
Consider a mid-size general contractor running 15 active projects. Without three-way matching, a concrete supplier submits an invoice for 80 cubic yards delivered to Job 2204. The PO was for 60 yards. The field superintendent signed a delivery ticket for 60 yards. But because AP never compares these documents, the company pays for 80 yards. Multiply that across hundreds of monthly invoices and the financial leakage becomes significant.
Scenario 1: Duplicate invoice without matching. A mechanical subcontractor's supplier sends Invoice #4410 for copper fittings on Job 1987, Phase 3, cost code 22-400. Two weeks later, the same supplier resubmits the invoice with a slightly different format as Invoice #4410-R. Without matching against the original PO and receiving records, AP pays both. The $11,200 duplicate goes unnoticed until the quarterly job cost review.
Scenario 2: Partial delivery matched correctly. An electrical contractor orders 2,000 feet of 3/0 copper wire on PO-6650 for a hospital project. The distributor ships 1,200 feet in week one; the field team logs receipt of 1,200 feet. When the invoice arrives for 2,000 feet, the three-way match catches the 800-foot discrepancy. AP holds payment and contacts the vendor. The remaining 800 feet ships the following week, a second receipt is logged, and only then is the full invoice released.
Scenario 3: Cost code mismatch caught at matching. A GC purchases form lumber for Job 3301, cost code 03-100 (concrete formwork). The vendor invoice lists the charge against Job 3301, cost code 06-100 (rough carpentry). The three-way match flags the cost code conflict. The AP team corrects the coding before posting, keeping the WIP schedule accurate and preserving the integrity of the concrete budget line.
Manual three-way matching — printing POs, stapling delivery tickets to invoices, and walking paper between desks — does not scale beyond a handful of projects. Modern construction finance teams use AP automation platforms that digitize all three documents and match them programmatically.
Vergo is a card-agnostic expense management platform built for construction. Connect any corporate or project credit card and get full visibility and control over field spending.
Two-way matching compares only the purchase order and the vendor invoice. Three-way matching adds the goods receipt or delivery confirmation as a third checkpoint. In construction, three-way matching is preferred because materials often ship to remote jobsites where deliveries can be partial, delayed, or misdirected without field verification.
Each partial delivery generates its own receiving record. The matching system tracks cumulative quantities received against the original PO. When a vendor invoice arrives, it is compared to the total received to date. Payment is approved only for the quantity actually delivered and confirmed by the field team.
Responsibility is shared. Field superintendents or warehouse staff confirm receipt of materials. The purchasing team issues and maintains POs. The AP team performs the actual match and resolves discrepancies. A project controller or finance manager typically sets the tolerance thresholds and reviews exception reports.
Most construction firms set a quantity tolerance of 5–10% and a price tolerance of 1–3% to accommodate rounding, freight adjustments, and minor delivery variances. Invoices within tolerance auto-approve. Those exceeding tolerance require manual review. Thresholds vary by material type — bulk commodities like aggregates tend to have wider tolerances than precision items.
Yes. AP automation platforms designed for construction can extract invoice data via OCR, match it against PO and receiving records stored in the ERP, and flag exceptions automatically. Vergo, for example, performs line-item matching across job codes, cost codes, and quantities, then routes exceptions to the appropriate reviewer.