By Paras Saini & Shubham Sharma ·
Invoice Tracking for Construction — Retentions, Progress Claims & Late Payments
Progress claim 4 was submitted six weeks ago. The certified amount was 90% of what you claimed. The payment arrived at 80% of the certified amount. The shortfall is £14,000 — and you've mentally filed it as “close enough, there's always claim 5.” That £14,000 compounds. By practical completion you have three months of uncollected shortfalls, plus £60,000 in retention that became due eight months ago and is sitting in the developer's account because you don't have a system that flags retention release dates. Construction has the worst late payment rates of any industry — with average DSO (days sales outstanding) of 70–90 days — and most of it is structural. This is the tracking system built for how construction billing actually works.
Key takeaways
- Every construction invoice has three different numbers you must track separately: gross billed, net certified, and actual payment received. A gap between certified and paid is a payment dispute; a gap between billed and certified is a certification dispute — different responses required.
- On a $2M contract at 5% retention, $100,000 is sitting in the developer's account. Most contractors track the progress claims; almost none track the retention release dates with equal rigour.
- Mentally discounting partial non-payment ('they paid most of it, close enough') is how uncollected shortfalls compound to a full claim's value by project end.
- UK HGCRA: if no valid Pay Less Notice is served before the final payment date, the notified sum is due in full — this is your strongest collection tool and most contractors never use it.
- Subcontractor payment chains need a separate AR view: you need to see your receivables and your payables timing together to know which overdue invoice to chase first.
Why Construction AR Is Different
Most invoice tracking tools are built for simple billing: one invoice, one amount, one due date, one payment. Construction billing does not work like this. A single project generates multiple progress claims over months or years, each with gross amounts, retention deductions, variations, set-offs, and disputes layered on top. The final sum received for any invoice is almost never the same as the sum billed.
According to industry data, construction has the highest late payment rates of any sector — with 70–90 day average DSO in many markets. UK construction businesses can use the HMRC invoice requirements as a baseline for all their commercial invoices. The cause is structural: complex payment chains (developer → head contractor → subcontractor → sub-subcontractor), long project timelines, retention holdbacks, and disputed variations create multiple points where payment stalls. Tracking construction AR properly means tracking each of these components separately.
The Core Problem: Retention Leakage
The single largest tracking failure in construction is retention. Retention — typically 5–10% held back from each progress payment until practical completion, then a further 50% held until defects liability period ends — is chronically under-tracked. Contractors know roughly how much retention they are owed, but rarely have a system that flags when each retention tranche becomes due for release. The result: retention sits in client accounts for 6–12 months beyond its due date, and contractors only chase it when cash flow becomes critical.
On a $2M contract at 5% retention, that is $100,000 sitting in someone else's account. Tracked and chased proactively, it releases on schedule. Untracked, it becomes a negotiation.
What to Track on Every Construction Invoice
A construction invoice record needs more fields than a standard invoice. For each progress claim or invoice, track:
| Field | Why It Matters |
|---|---|
| Claim / invoice number | Links to the payment application and contract schedule |
| Claim period / stage | Identifies which phase of the project this covers |
| Gross amount claimed | What you billed before deductions |
| Retention deducted | The hold-back amount (typically 5–10%) |
| Variations included | Approved vs. disputed variations tracked separately |
| Net certified amount | What the client's certifier approved for payment |
| Net payable amount | What should actually be paid this period |
| Payment due date | Based on contract terms or statutory timeframe |
| Actual amount received | What was actually paid — partial payments noted |
| Shortfall / dispute | Any unpaid amount and the reason given |
| Retention release date | Practical completion + defects period = retention due date |
| Chase history | Date and method of each follow-up contact |
The most important distinction: track gross billed, certified amount, and actual payment as three separate numbers. A gap between certified and paid is a payment dispute. A gap between billed and certified is a certification dispute — both need different responses.
Progress Billing & Milestone Invoices
Progress billing is the standard billing method for longer construction contracts: work is invoiced at agreed stages (e.g., 20% on foundations, 40% on structure, 60% on fit-out) or on a monthly basis based on percentage complete. Each progress claim becomes a separate invoice record.
The Progress Billing Chase Problem
The problem with progress billing is that contractors often mentally discount partial non-payment — "they paid most of claim 3, close enough" — because there is always another claim coming. This compounds: if 5% is withheld on each of 10 progress claims, the uncollected shortfall is 0.5 claims by the time you hit practical completion. Chase each claim to full payment before submitting the next one.
How to Manage Multiple Concurrent Projects
If you have multiple projects with progress billing running simultaneously, a spreadsheet quickly becomes unmanageable — tracking 4 projects × 6 claims each × multiple status fields across rows is error-prone and provides no visual overview of which claims are overdue. A visual tracker that groups invoices by project and shows overdue status at a glance is significantly more reliable.
See invoice tracking for small business for the general system, and AR aging report tool for a snapshot of your receivables position across all jobs.
Retention Tracking — The Amount Nobody Chases
Retention is structurally designed to be forgotten. It is deducted from every payment, accumulated over months, and only released at specific project milestones — which are often poorly defined and easy for clients to delay. Contractors who do not have a specific system for retention tracking routinely leave it uncollected for 3–6 months beyond its release date.
The Two-Stage Retention Release
Most construction contracts have two retention release triggers:
- Practical completion: 50% of total retention released (e.g., if 5% retention was held, 2.5% is released at PC)
- End of defects liability period (DLP): Remaining 50% released — typically 6–12 months after PC
Both dates need to be tracked as hard deadlines in your AR system — exactly like an invoice due date — with follow-up reminders set for 2 weeks before each release point.
Calculating Your Total Retention Owed
At practical completion, calculate:
Total gross billed × retention % = total retention held
Retention at PC = total retention × 50%
Retention at DLP = total retention × 50%
Issue a specific retention release invoice at each milestone — do not rely on the client to initiate. State the contract clause, the milestone date, and the exact amount due.
Managing Subcontractor Payment Chains
Head contractors face a dual AR problem: they are chasing payments from above (developer or principal) while managing payments to below (subcontractors). The timing mismatch between these two is a major source of cash flow strain. Use the cash flow calculator to quantify exactly how much working capital is tied up in outstanding invoices at any point in a project.
The Pay-When-Paid Problem
Pay-when-paid clauses — which make subcontractor payment conditional on the head contractor receiving payment from the principal — are restricted or unenforceable in many jurisdictions (banned for construction contracts in the UK, restricted in several Australian states). Where they remain in force, they create a chain reaction: one late payment at the top delays every subcontractor below.
Whether or not pay-when-paid clauses apply to you, track your subcontractor payment obligations alongside your receivables. Knowing exactly when you need cash to pay subcontractors is how you prioritise which of your own overdue invoices to chase first.
Subcontractor Invoice Processing
Set a fixed claim day for subcontractors (e.g., last working day of the month) to batch process their invoices. Assess each claim against your contract programme and the approved scope — return any claim that does not match with a specific reason. Issue your payment certificate within the contractually required timeframe. Document every decision with written notices.
The Construction Invoice Chase Process
The escalation sequence for construction invoices follows the same logic as other industries — but the stakes and timeframes are different. A 30-day overdue invoice on a $5,000 freelance project is a nuisance. On a $500,000 progress claim, it is a business-critical situation requiring immediate formal action.
Email confirming the payment application was received, ask for ETA on payment or the payment certificate. Often resolves admin delays quickly.
Second written notice. Reference the contract clause and the due date. Request the specific reason for delay in writing. Follow up by phone.
Formal demand referencing the contract. State the specific amount due, any applicable late interest, and the statutory rights available (adjudication, suspension of works if available under contract).
Issue a formal notice of intention to suspend works (where your contract or Security of Payment legislation allows). This is often enough to prompt immediate payment.
Refer to adjudication (under Construction Act / Security of Payment), engage a construction solicitor, or commence small claims / county court proceedings depending on amount.
Use the invoice follow-up schedule planner to set exact chase dates from your invoice due date. For payment reminder templates, the payment reminder email generator covers friendly through escalation tones.
Late Payment Laws for Construction
Construction has some of the strongest statutory late payment protections of any industry — but they only work if you use them.
UK — Housing Grants, Construction and Regeneration Act (HGCRA)
- Applies to most commercial construction contracts (not residential occupiers)
- Payer must issue a Payment Notice within 5 days of payment due date
- To pay less, a Pay Less Notice must be served at least 7 days before final date for payment
- Without a valid Pay Less Notice, the notified sum is due in full
- Contractors can suspend works after 7 days written notice for non-payment
- Adjudication available for any construction dispute — decision within 28 days
- Late Payment of Commercial Debts Act: 8% above BoE base rate interest + fixed recovery costs
Australia — Security of Payment (state-based legislation)
- Each state has its own Act (Building and Construction Industry Security of Payment Act or similar)
- Contractors can serve a Payment Claim on their payment schedule
- Respondent must serve a Payment Schedule within 10–15 business days
- Failure to serve a Payment Schedule means the claimed amount becomes due in full
- Adjudication available for disputed claims — typically 10 business day decision
- Right to suspend works after serving a Suspension Notice
USA — Federal & State Prompt Payment
- Federal Prompt Payment Act: federal agencies must pay within 30 days
- Most states have their own prompt payment laws for public and private projects
- Mechanic's lien rights give contractors secured rights against the property
- Preliminary notice requirements vary by state — must be served early in the project
- Bond claims available on federally funded projects (Miller Act) and many state projects
For the full escalation guide when a client refuses to pay, see what to do when a client refuses to pay and unpaid invoice small claims court.
Invoice Tracking Tools for Construction
Most invoice tracking tools are not built for construction billing — they assume one invoice = one payment = one amount. Construction contractors need:
- Progress claim tracking: Separate records for each claim with gross/net/retention fields
- Retention ledger: Total retention held per project, with release date tracking
- Multi-project view: An AR overview across all active jobs — not just one project at a time
- Chase history: A log of every contact attempt per invoice, with dates and methods
- Overdue flags: Visual indicators when a payment is overdue — including retention past its release date
- Dispute tracking: Ability to note disputed amounts separately from accepted shortfalls
Spreadsheets: Work for 1–2 concurrent projects with simple billing. Become unreliable as project complexity and volume increases — formulas break, retention dates get missed, multi-project views are impossible without significant manual effort.
General accounting software (QuickBooks, Xero): Good for bookkeeping and financial reporting, not built for construction progress billing or retention management.
Construction-specific tools: Platforms like InvoiceGrid allow you to track invoice status, overdue amounts, and chase history per client — providing the AR visibility that general tools lack. For the comparison, see invoice tracking: spreadsheet vs software.
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Frequently Asked Questions
A developer paid 80% of my certified amount with no explanation — what do I do?+
First, check whether a Pay Less Notice (UK) or equivalent withholding notice was served before the final payment date. If no valid notice was served, the full certified sum is due — not the reduced amount. Respond in writing immediately requesting the specific contractual basis for any deduction. Vague 'set-off' claims without a served notice are often unenforceable. If no notice was served and they still refuse to pay the full certified amount, this is a straightforward adjudication case under the UK HGCRA or equivalent Security of Payment legislation in your jurisdiction.
How do I track progress billing invoices without losing track of shortfalls?+
Each progress claim needs its own invoice record with five tracked numbers: gross billed, retention deducted, net certified amount, net payable, and actual received. Track the gap between certified and received as a separate 'shortfall/dispute' field. A partial payment is not a full payment — if claim 4 was certified at £80,000 and you received £72,000, that £8,000 shortfall must be tracked and chased separately, not absorbed. A spreadsheet works for one or two projects; once you have multiple concurrent jobs with multiple claims each, a dedicated tracker is the only reliable approach.
My retention was due at practical completion 6 months ago — how do I chase it now?+
Issue a specific retention release invoice referencing the practical completion date, the contract clause covering retention release, and the exact amount due. Do not rely on the developer to initiate — they will not. If the retention is genuinely overdue (practical completion date has passed), you have a payment claim under the same legal framework as any overdue invoice. Escalate through the standard construction dispute process: direct request, formal demand, adjudication if not resolved within 14 days.
Can I charge late fees on construction invoices?+
Yes — and in the UK, the right to statutory interest is automatic on commercial construction debts under the Late Payment of Commercial Debts Act, with no contractual clause required. The rate is 8% above the Bank of England base rate per annum, plus fixed debt recovery costs (£40/£70/£100 depending on amount). You can also claim reasonable debt recovery costs. In Australia, Security of Payment legislation provides adjudication rights for disputed claims. In the US, mechanic's liens and prompt payment laws provide similar remedies depending on state.
What is a Pay Less Notice and why does it matter to my cash flow?+
A Pay Less Notice (or withholding notice under the UK HGCRA) is the formal document a developer or head contractor must serve if they intend to pay less than the notified sum — usually at least 7 days before the final payment date. If no valid Pay Less Notice is served, the full notified sum is due in full, regardless of any dispute. This is one of the most powerful collection tools available to UK contractors, and most never use it. If a developer routinely pays less without serving proper notices, each underpayment is recoverable through adjudication.
Related: Late payment statistics 2026 · Invoice tracking for small business · What to do when a client refuses to pay · How to charge late fees · AR aging report tool