Finance

What is accounts payable in construction?

Accounts payable is the money a contractor owes to subcontractors, suppliers, equipment rental companies, and other vendors for work and materials already received but not yet paid.

An office manager and contractor review invoices with a calculator and laptop in a construction office.
Review invoices, committed costs, and cash timing together before making project decisions. AI-generated illustration.

Accounts payable (AP) is the list of bills a contractor owes and has not paid yet. In construction that means subcontractor pay apps, supplier invoices, equipment rentals, dump fees, and the rest. On the balance sheet AP is a liability. On a job it is a cost, and the way it gets coded decides whether the job cost report tells the truth.

How construction AP differs from regular AP

A retail store pays a vendor and books the expense. A contractor has extra layers on almost every bill:

  • Job and cost code. Every invoice needs a job number and a cost code, so the drywall supplier's bill hits drywall on the right project.
  • Commitments. Most costs were promised earlier on a subcontract or purchase order. The bill should be checked against what was committed.
  • Retainage payable. When the GC holds 10 percent from a sub, the unpaid portion stays on the books as retainage payable until release.
  • Lien waivers. Paying a sub without collecting a lien waiver can expose the owner, and the GC, to a lien for money already paid.
  • Payment terms tied to the owner. Pay-when-paid and pay-if-paid clauses link AP timing to when the GC collects.

Example: one supplier invoice

Say a framing contractor receives a $24,600 lumber invoice. The PO was for $23,900. The extra $700 is a delivery fee for a second drop that the PM asked for after a crane delay. Before it gets paid, the office should match three things: the PO, the delivery ticket signed in the field, and the invoice. That is the classic three-way match.

Three-way match on a lumber invoice
DocumentAmountStatus
Purchase order$23,900Approved
Delivery tickets (2 drops)Signed by foremanReceived
Invoice$24,600Hold $700 for PM approval

The PM approves the $700, codes it to the job's general conditions or to the change order if the delay was owner-caused, and the bill moves to the next check run. If the delay was the owner's fault, that $700 belongs on a change order request, or it is lost.

Common AP mistakes in construction

  1. Coding bills to the wrong job, which makes one project look great and another look terrible.
  2. Paying subs before their certificate of insurance and lien waiver are current.
  3. Losing track of retainage payable, then paying it twice or paying it before the owner releases the GC's retainage.
  4. Approving invoices by email with no record of who said yes.
  5. Letting invoices sit in a PM's truck for three weeks, so committed cost is unknown at month end.

Related terms

AP is the mirror image of accounts receivable. It ties to committed cost, job costing, and the WIP report. To catch costs before the bill shows up, see how to track committed costs before invoices arrive. Smart Business Automator links each sub and vendor bill to its job and change order, and tracks insurance and lien waiver status before payment.

Frequently asked questions

Is accounts payable an expense?

AP itself is a liability, money owed. The underlying cost is recorded as an expense, or as job cost for construction, when the bill is entered.

What is retainage payable?

The part of a subcontractor's earned billing the contractor is holding back under the subcontract. It stays a liability until the release conditions are met.

Who approves AP invoices at a construction company?

Usually the project manager approves job-related bills against the budget and commitment, and the controller or owner approves the check run.

How often should a contractor pay bills?

Many pay weekly or twice a month. The subcontract terms, any state prompt payment rules, and pay-when-paid clauses set the real deadlines.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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