Billing and cash flow

How to bill retainage correctly

Bill the full value of work each period, show retainage as a separate deduction at the rate your contract and state law allow, track the running balance by job and by sub, and send a separate release invoice the day you qualify.

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.

Billing retainage correctly comes down to three things. First, bill the gross value of work completed each period and show retainage as its own deduction, never as a smaller line value. Second, apply the right rate to the right base, which depends on the contract, any reduction milestones, and state or federal limits. Third, keep a running retainage balance per job and per subcontract, then bill the release with its own invoice or final pay application as soon as the trigger is met. Most retainage losses are not legal disputes. They are money nobody remembered to bill.

Step 1: Confirm the rate, the base, and the limits

Read the prime contract and every subcontract for four things: the percentage, what it applies to (completed work only, or stored materials too), any reduction (for example after 50 percent complete), and the release trigger. Then check the law that applies, because it can override the contract.

  • Federal fixed-price construction. Under FAR 52.232-5, the contracting officer authorizes full payment when progress is satisfactory and may retain a maximum of 10 percent of a payment only when progress is not satisfactory. FAR 32.103 says retainage should not be used as a substitute for good contract management and caps it at 10 percent of the approved estimated amount. Retainage also does not apply to the part of a progress payment covering bond premiums.
  • Federal subcontracts. 31 U.S.C. 3905 lets the prime and sub agree to retain a specified percentage of each progress payment, but the prime cannot request payment from the agency for amounts withheld from a sub until it certifies the sub is entitled to them.
  • State rules. Some states cap retainage on public work and some on private work. California is an example: Civil Code section 8811 limits retention on private works contracts entered into on or after January 1, 2026 to 5 percent of each payment and 5 percent of the contract price, at every tier, with exceptions for certain unbonded subs and residential projects of four stories or less. Check your state on the prompt payment and retainage laws by state pages.

Step 2: Calculate retainage on every pay application

On the AIA G702, retainage sits on line 5, split between completed work and stored material. Bill the full earned amount in columns E and F of the G703, total it on line 4, then calculate retainage on that cumulative total. If retainage varies by line, AIA's G703 instructions say to use column I. If one rate applies to the whole contract, column I can stay blank.

Calculate retainage on the cumulative total, not just this period. That way a mid-job rate change or an architect's adjustment flows through automatically, and line 5 always reflects the true amount held.

For a general contractor, the pay app you send the owner and the pay apps you approve from subs have to agree. If the owner holds 5 percent on the electrical line and you hold 10 percent from the electrician, your books show more cash in hand than the sub's ledger expects, and that gap has to be explained at closeout. Build a simple monthly check: retainage held by the owner on each trade line, next to retainage you hold from the sub on that line. Any line where you hold more needs a contract reason.

Step 3: Handle reductions when you hit the milestone

If the contract steps retainage down at a milestone, do not assume the owner will do it for you. Put a written request with the pay app that crosses the threshold, cite the contract section, and show the math. Some contracts reduce the rate going forward; others release the excess already held. Read which one yours says, because the dollar difference is large.

Worked example: a drywall sub with a rate reduction

As an example, say a drywall sub has a $300,000 subcontract with 10 percent retainage, reducing to 5 percent on all work once the job is 50 percent complete (this is a contract term in the example, not a statutory rule). Month four takes cumulative completed work to $165,000, which is 55 percent.

Example: retainage before and after a contract reduction
ItemMonth threeMonth four
Total completed to date$120,000$165,000
Retainage rate (per subcontract)10%5%
Total retainage held$12,000$8,250
Total earned less retainage$108,000$156,750
Less previous certificates$76,500$108,000
Current payment due$31,500$48,750

Month four's payment is $48,750, not $40,500. That $8,250 difference is retainage released by the reduction. If the sub applied the new 5 percent only to this month's $45,000 and left the earlier $12,000 alone, the pay app would show $14,250 held instead of $8,250, leaving $6,000 sitting with the GC until closeout, months away.

Step 4: Track retainage by job and by sub

General contractors carry two balances on every job: retainage receivable from the owner and retainage payable to each sub. Keep both in separate ledger accounts, and reconcile them monthly against the pay app. Your AR aging should show retainage in its own column, because it is not late until the release trigger passes. A retainage tracking template with job, sub, rate, amount held, trigger, and expected release date is enough for a small company.

Step 5: Bill the release

Retainage is rarely paid automatically. When the trigger is met (substantial completion, final completion, owner acceptance, or a partial release for a finished phase), send a retainage release invoice or final pay application that shows contract sum, total completed, retainage held, and amount requested, with the closeout package attached. On federal jobs, FAR 52.232-5 ties final payment to completed and accepted work, a properly executed voucher, and a release of claims. See how to get retainage released faster for the closeout side.

Mistakes to avoid

  • Reducing line values to net out retainage, which breaks the SOV and makes the release invisible.
  • Calculating retainage only on this period's work, so rate changes never flow through.
  • Withholding retainage on stored materials or bond premiums when the contract or FAR says not to.
  • Holding a higher rate from subs than the owner holds from you.
  • Never invoicing the release. Retainage receivable that is two years old is often money nobody asked for.
  • Signing an unconditional final lien waiver before the retainage check clears.

Tools that help

Use the retainage tracking template and the construction invoice template for release invoices. Related terms: release of retainage and progress billing. Smart Business Automator calculates retainage on each pay app, keeps receivable and payable balances per job and per subcontract, and flags jobs that have reached their release trigger. See construction accounts receivable automation.

Frequently asked questions

Is retainage calculated on stored materials?

It depends on the contract. The AIA G702 shows retainage on completed work and on stored material separately, and many contracts withhold on both. Some contracts and some state laws treat stored material differently, so check before you bill.

Do I pay sales tax or recognize revenue on retainage?

Retainage is usually recorded as earned revenue with a separate retainage receivable, even though cash comes later. Tax treatment varies by state and accounting method, so confirm with your CPA.

What is the maximum retainage on federal construction jobs?

FAR 32.103 caps retainage at 10 percent of the approved estimated amount, and FAR 52.232-5 allows retaining up to 10 percent of a payment only when progress is not satisfactory.

Can a general contractor hold more retainage from a sub than the owner holds?

Unless a statute prevents it, the subcontract controls. Some states bar it. California's Civil Code section 8811, for private contracts entered into on or after January 1, 2026, limits a subcontract's retention percentage to the percentage in the owner's contract.

Sources

  1. Acquisition.gov: FAR 52.232-5, Payments under Fixed-Price Construction Contracts
  2. Acquisition.gov: FAR 32.103, Progress payments under construction contracts
  3. Cornell LII: 31 U.S.C. 3905, Payment provisions relating to construction contracts
  4. California Civil Code section 8811, retention on private works (public.law)
  5. AIA Contract Documents: Instructions for G703-1992, Continuation Sheet
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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