Three-way match in construction: check every supplier bill before you pay

What a three-way match in construction checks

A three-way match in construction is the check accounts makes before paying a supplier. Three documents should agree: the purchase order (what you agreed to buy, at what rate), the delivery ticket signed on site (what actually arrived) and the supplier's bill (what you are being asked to pay). If they agree, the bill is paid. If they don't, only the part they agree on is paid and the rest waits for an answer.

Each document answers a different question, and each comes from a different person. That is what makes the check work. A supplier can't invent a delivery the site never signed for, and a site can't sign for something nobody ordered.

Government buyers follow the same logic. US federal rules base payment on a proper invoice backed by a receiving report that records the contract number and the quantities received and accepted (FAR 32.905). A builder doesn't need the paperwork of a federal agency, but the principle carries over: pay against evidence of receipt, not against the bill alone.

Why matching is harder on a construction site

The textbook three-way match assumes one order, one delivery and one bill. A site breaks that assumption almost every week:

• Partial deliveries. One steel order arrives in three trucks over ten days, but the supplier sends one bill for the full order, sometimes before the last truck.
• Tickets signed far from the office. The proof of receipt is a paper slip in a site engineer's pocket. If it never reaches accounts, the bill gets paid in full by default.
• Different units. Steel is ordered by the tonne, counted on site as bars and billed on weighbridge weight. Concrete is ordered and billed by volume and arrives as truckloads.
• Prices that move. Steel and cement rates change between the quotation and the bill. The bill quietly shows today's rate instead of the agreed one.
• Extras that were never ordered. Delivery charges, unloading, pump hire, fuel surcharges or a substituted brand appear on the bill but not on the order.
• Rejected material. Broken bags, bent bars or a load of concrete sent back still show up on the bill unless someone raises it.

None of these mean the supplier is dishonest. Most mismatches are timing and paperwork. But each one pays out money for something you didn't receive or didn't agree to, and on a job running at a thin margin, that comes straight out of profit. It also distorts your construction budget vs actual report, because the cost lands before the material does.

How to do a three-way match, step by step

1. 1Give every order a number.
   The purchase order lists each item, quantity, unit, rate, the delivery site, who receives and what is included in the rate (delivery, unloading). Ask the supplier to quote the PO number on every ticket and bill.
2. 2Receive against the order on site.
   The receiver counts or measures before signing, writes the actual quantity on the ticket, notes anything short, damaged or rejected, and photographs the signed ticket. Never sign a blank or 'received in good order' ticket you haven't checked.
3. 3Get the ticket to the office the same day.
   A photo on a shared channel or in your system is enough. The rule is simple: a delivery the office can't see doesn't count as received.
4. 4Match line by line when the bill arrives.
   For each line, compare item, quantity, unit and rate across the three documents. Add up the accepted quantity from every ticket that belongs to that order, not only the latest one.
5. 5Split the bill into 'matches' and 'held'.
   Approve what matches. Put each difference on hold with a reason: not yet delivered, rate above order, not on order, rejected on site.
6. 6Resolve the held part in writing.
   A later delivery, a credit note from the supplier or a revised purchase order approved by whoever approved the original order. Then release it.
7. 7Pay, and charge the cost to the job.
   Record the payment against the project and phase the material was bought for, so job costing stays right. See construction expense tracking for how to tag costs.

Worked example: a steel and cement bill

Here is a realistic bill with three common problems in it. The figures are sample numbers, not market rates.

The order (PO-0142): 5.0 tonnes of 12 mm steel bar at $780 per tonne, and 400 bags of 50 kg cement at $9.50 per bag, delivery included in both rates. Steel arrived in two loads: ticket 5521 for 2.5 t and ticket 5538 for 1.8 t, so 0.7 t is still to come. Cement arrived on one ticket: 400 bags delivered, 4 torn bags rejected and sent back, 396 accepted. The supplier's bill asks for 5.0 t of steel at $795, 400 bags of cement at $9.50, and $60 delivery.

The bill total is $7,835. The amount that matches is $7,116, and $719 (about 9% of the bill) waits for answers. Notice that two problems overlap on the steel line: paying 5.0 t at the agreed $780 would still overpay for 0.7 t that never arrived, and paying 4.3 t at the billed $795 would accept a rate nobody approved. Checking only the bill total against the order total ($7,700 ordered against $7,835 billed) would have flagged $135 and missed most of it.

What happens next: the supplier delivers the last 0.7 t and that quantity is released at $780 ($546). The rate difference and the delivery charge are either withdrawn with a credit note or, if the price rise was genuine and agreed, approved as a revised order. The rejected cement is credited or replaced.

Matching when the units don't agree

Most construction mismatches that look like fraud are really unit problems. Settle the basis of measurement in the purchase order, before the first truck arrives:

• Steel bar by weight. Say whether you pay on weighbridge weight or theoretical weight. Theoretical weight per metre in kg is the bar diameter in mm squared, divided by 162 (from steel's density of about 7,850 kg/m³). A 12 mm bar weighs about 0.888 kg/m, so a 12 m length is about 10.7 kg and 4.3 t is roughly 400 bars. If the site counts bars, the office can convert the count to tonnes. Real bars vary a little from the theoretical figure, so agree which number governs.
• Cement and bagged material by count. Pay per bag accepted. 20 bags of 50 kg make a tonne, if the supplier bills by the tonne.
• Ready-mixed concrete by volume. Each truck should come with a batch ticket showing the plant, ticket number, date, truck, mix class, volume and batching time. Building departments such as Miami-Dade County list these items for ready-mix tickets. Add up the tickets per pour and match the bill to that sum, not to the volume on the order.
• Aggregates and sand by load or weight. A truck 'load' means different things to different suppliers. Specify cubic metres or tonnes, and record the vehicle number on every ticket.
• Pieces, lengths and packs. Tiles by box or square metre, pipe by length, cable by drum or metre. Write both the order unit and the billing unit on the PO if they differ.

What to do with each kind of mismatch

Decide your tolerances in writing, so accounts isn't making judgement calls on every bill. A tolerance is the difference you accept without querying. Sensible starting points, which you should adjust to your own work, are: no tolerance on counted items such as bags, pieces and boxes; a small, written tolerance on weighed or measured bulk material, where scales and loads genuinely vary; and no tolerance on rate unless the order says the price is fixed on the day of delivery.

Who should order, receive and approve

The match only protects you if three different people produce the three documents. Splitting key duties among different people to reduce the risk of error or fraud is called segregation of duties, and it is a core principle of internal control (GAO Green Book). If one person can order, sign for the delivery and approve the bill, the match is that person checking their own work.

• Orders: the project manager or purchaser raises the purchase order after the demand is approved.
• Receiving: the storekeeper or site engineer signs the ticket and records the accepted quantity.
• Matching and payment: accounts matches and the owner or a named manager approves payment above a set amount.

A small builder with three people in the office can still do this. The owner approves orders and payments, the site signs for deliveries, and whoever does the books does the match. What matters is that no single person controls all three steps. The construction material tracking guide shows where this fits in the full path from site demand to payment, and a regular site stock count catches what slips past receiving.

Subcontractors and services: what replaces the delivery ticket

Work, unlike material, doesn't arrive on a truck. For subcontractors and labour, the 'receipt' is evidence of work done:

• Subcontract work: a measurement or progress record agreed on site, matched against the contract rates and the stage reached. Retention and advances are deducted as the contract says.
• Daily-wage labour: days and hours from the daily site report, matched against the agreed day rate before the pay run.
• Equipment hire: hours or days from the site log, matched against the hire rate and the dates the machine was actually on site.
• Fixed fees and services: a two-way match of the bill against the agreed fee is usually enough.

The same rule applies: pay for what was agreed and what was received, and hold the rest until it is explained.

Run it in a spreadsheet or in software

With a handful of orders a month, a match register in a spreadsheet works, alongside a construction project management Excel template. Use one row per order line with these columns: PO number, item, unit, quantity ordered, rate ordered, ticket numbers, quantity accepted, bill number, quantity billed, rate billed, approved amount, held amount, reason held, date resolved. Filter on 'held' every week and chase each one.

The spreadsheet breaks down when tickets stay on site, several projects buy from the same supplier and nobody updates the register before the bill is paid. At that point the match needs to happen where the order and the receipt are already recorded. In construction procurement software, the order, each partial receipt with its photo and the bill sit on one record, so the match is a comparison, not a hunt for paper. Received material also lands in the site store, and paid bills flow into project costing.