Accounts receivable and collections for construction: challenges and how to fix them

Construction accounts receivable is complex because payment is tied to milestones, paperwork, and deadlines rather than a simple invoice and due date. A contractor bills progress as work completes, the owner withholds retainage until the project closes, lien rights expire on a strict legal clock, and subcontractors often wait under pay-when-paid terms for the money to flow down the chain. Each of these adds a way for cash to get stuck.

That makes construction collections a documentation and deadline discipline. The firms that get paid fastest are the ones that bill accurately, never miss a lien or notice deadline, and follow up relentlessly on retainage and approvals that would otherwise drift for months.

What makes construction AR uniquely complex

Several traits set construction receivables apart from standard B2B billing.

• Milestone-based payment. Invoices follow progress and schedules of values, not a single sale, so each one needs approval before it pays.
• Retainage. A slice of every payment is withheld until closeout, financing the contractor in the meantime.
• Legal deadlines. Lien rights and preliminary notices expire on dates that vary by state and project type, and a missed deadline can forfeit the right to get paid.
• Payment chains. Pay-when-paid and pay-if-paid clauses tie a subcontractor's payment to the general contractor receiving funds first.
• Long project timelines. A single job can run for a year or more, so a balance can be earned in month two and not fully collected until well after the project ends.

The work is less about chasing forgetful customers and more about managing a stack of conditional, time-sensitive claims to cash. Each open balance carries its own set of preconditions, who has to approve what, what documentation must be on file, and which deadline is running, and the payment moves only when all of them are satisfied.

Progress billing and retainage

Progress billing means cash comes in pieces as the project advances, each tied to a schedule of values and an owner or architect approval. An error or a missing lien waiver can hold up an entire pay application, so accuracy and complete documentation directly determine how fast the payment clears.

Retainage is the bigger drag on cash. The owner withholds a percentage of each progress payment, often 5 to 10 percent, until the project is substantially complete and the closeout paperwork is done. That withheld amount can sit for months after the work is finished. Across several active projects, retainage adds up to a large, slow-moving receivable that needs active follow-up as each job closes, or it drifts well past when it is due.

The scale of it surprises people. Take a contractor running 20 million dollars of work a year with 8 percent retainage. At any given time roughly 1.6 million dollars is being held back, earned but uncollectable until projects close and the paperwork clears. If closeout follow-up is loose and that retainage releases three months later than it should on average, the contractor is financing 1.6 million for an extra quarter, every year, on work already delivered. None of that is disputed. It is simply withheld cash that nobody chased. Treating retainage like any other overdue balance, with a deliberate follow-up cadence tied to each project's closeout, is what gets it released on time.

Lien rights and compliance deadlines

Lien rights are the contractor's strongest tool for getting paid, but they only exist if the deadlines are met. Preliminary notices, notices of intent, and lien filings each have a window that varies by state and by the contractor's role on the project. Miss one and the right to lien can be lost, which removes the leverage that secures payment.

That makes deadline tracking part of the AR job in construction. Every project carries its own calendar of notices and filing dates that must be hit regardless of how collections are otherwise going. A contractor working in several states is tracking several different rule sets at once, each with its own clock running from a different trigger, like first furnishing of materials or last day on site. The cost of a missed date is not a late payment, it is a forfeited claim, so this is one area where letting something slip through the cracks is genuinely expensive. A single missed preliminary notice can strip the leverage from a six-figure receivable, leaving the contractor with nothing but a polite request and no legal recourse.

Pay-when-paid and slow approvals

Pay-when-paid and pay-if-paid clauses push the timing risk down the chain. A subcontractor's invoice does not come due in the normal sense, it comes due when the general contractor gets paid by the owner. So a sub can do everything right and still wait, because the bottleneck is upstream.

Slow approvals compound it. Pay applications route through project managers, architects, and owners, any of whom can sit on an approval or kick it back over a minor discrepancy in the schedule of values or a missing lien waiver. Each handoff is a place the payment can stall, and on a long project the same application can bounce through several reviewers before a dollar moves. The collections task is to keep the documentation moving, confirm where each pay application stands, and follow up the moment an upstream payment lands so the downstream balance is requested immediately, not weeks later. Where a balance is genuinely contested, a clean dispute and deduction process keeps it from stalling the rest of the pay application while the disagreement gets resolved.

Automating construction collections

The deadline tracking and relentless follow-up that construction AR demands is exactly the kind of consistent, rules-driven work an agentic AR system handles well. Rex tracks every open balance across projects continuously, including retainage that is coming due as a job closes, and follows up the moment something is payable instead of months later.

Rex keeps the paperwork moving: confirming where pay applications stand, chasing the approvals and documents that unblock payment, and surfacing the conditional balances waiting on an upstream payment so they get requested as soon as the money flows down. It carries each project's deadline calendar in the background, flagging the notices and filings that are coming due before the window closes rather than after, so the leverage that secures payment is never lost to a missed date. Judgment calls, like how to handle a strained relationship with a key general contractor or whether to file a lien, route to a person. The routine deadline tracking and follow-up runs on its own, so no retainage balance or notice deadline slips because someone was busy.

Getting paid faster on every project

When the follow-up runs consistently, construction cash moves faster. Retainage gets released closer to when it is due instead of aging for months after closeout. Pay-when-paid balances get requested the moment upstream cash lands. Pay applications clear faster because the documentation and approvals are chased proactively rather than after they stall.

The cash impact is direct. Retainage released a quarter earlier, on a book where seven figures are typically held back, is a large, recurring boost to working capital that costs nothing but follow-up. Pay applications that clear faster mean less of each project is financed out of the contractor's own pocket while it waits for approval.

The team's time shifts to where it matters: managing relationships with owners and general contractors, handling genuine disputes, and deciding when to use lien rights, while the deadline tracking and routine follow-up runs underneath. That is how a construction firm collects more of what it has earned, on every project, year after year.

See how Rex tracks deadlines and runs construction collections end to end.