Key Takeaways
- German construction firms carried trade receivables worth 9.7% of revenue in 2023, about 35 days, against 6.3% or 23 days across all industries (Deutsche Bundesbank, May 2026; days are our arithmetic).
- Three large US contractors carried 91 to 124 days of revenue in receivables including retainage at the end of 2025, with retention alone worth 20 to 44 days (10-K filings of EMCOR, Comfort Systems USA and Tutor Perini, February 2026).
- Retention adds days by contract, not by late payment: 10% of every bill held for a year is 36.5 days of DSO, 5% is about 18 days.
- Track four numbers: collectible DSO, retention days, unbilled days and days beyond terms.
- Apply a net payment to its pay application and keep the retention as its own open item; ClearMatch reaches a 95% auto-match rate with a person signing off every posting (Transformance customer data, 2026).
In This Article
- Key Takeaways
- What DSO is normal in construction?
- How much does retention add to DSO?
- How does progress billing set the clock?
- Which DSO numbers should a contractor track?
- How do you apply payments that arrive net of retention?
- Which part of construction DSO can you reduce?
- What do the retention rules look like now?
What DSO is normal in construction?
No official normal exists: German construction firms carry receivables worth about 35 days of revenue, while three large US contractors show 91 to 124 days including retainage.
Construction receivables in days of revenue: what the primary data says
Method: year-end balance divided by fiscal-year revenue, times 365, our arithmetic from the published figures. Bundesbank receivables include VAT while revenue excludes it, so the German days read slightly high. Public companies are not the whole industry and their contract mix differs: the table shows how far the definition moves the number, not a target.
Construction DSO is receivables divided by revenue times 365, a ratio that in construction depends on whether retention and unbilled work sit inside the receivable.
That is why the German figure looks low. In German commercial-code (HGB) accounts, work done but not yet billed usually sits in inventories, and inventories make up 56.2% of the construction sector’s balance sheet in the same Bundesbank table. The receivable holds only what has been billed.
Ranges such as 60-90 or 80-120 days circulate widely without a primary source behind them; the method above can be rerun on your own balance sheet. For the general formula, see the DSO formula with examples.
Late payment is real too: in ICAEW’s UK Business Confidence Monitor, 24% of businesses cited late payment as a growing issue, and construction reported the most late payments, at 37% (ICAEW, July 2026). More sector figures are in our accounts receivable statistics.
How much does retention add to DSO?
Retention adds about 20 days of revenue at EMCOR and Comfort Systems and 44 at Tutor Perini in their FY2025 filings; 10% held for a year adds 36.5 days.
The rule is arithmetic, not a benchmark: days added = retention held as a share of annual revenue x 365. If 10% of a full year’s bills is still held, that is 0.10 x 365 = 36.5 days; at 5%, about 18 days.
EMCOR’s receivables include $944.5 million of retainage billed at 31 December 2025, and the company expects about 90% of it to be collected during 2026 (EMCOR 10-K, February 2026). Comfort Systems reports retention of $506.5 million inside receivables and says customers typically withhold it for a period of six months (Comfort Systems USA 10-K, February 2026). MasTec puts retainage at generally 5% to 10% of billings (MasTec 10-K, February 2026).
One $12 million subcontract, three DSOs: what retention and approval time do (illustrative, USD)
Illustrative. Receivable / revenue x 365, measured on the last day of the project before any retention is released; gross bill $1.0m, net $900,000 (A, C) or $950,000 (B). Figures rounded to one decimal. Unbilled work between the cut-off and month end is left out here and appears as its own metric below.
In scenario A, 36.5 of the 63.9 days are retention: more than half of this DSO is a contract term.
Retention is billed but not yet due. A customer who pays the net amount on time is not a slow payer, so DSO including retention measures cash tied up, and days beyond terms measures collections.
Retention builds up during a project, peaks at completion and falls on release, so a growing contractor’s month-end DSO mixes new projects with old releases. Compare the same month across years.
How does progress billing set the clock?
Progress billing starts the clock at the pay application, so billing cut-off, certification and the contract’s payment period decide how many days pass before the net cash arrives.
A progress bill passes five stages, and each one adds days:
- Work done. Work performed early in the month waits, unbilled, for the billing cut-off.
- Pay application sent. In the US, the bill is a pay application showing the percentage complete per schedule-of-values line and the retention withheld.
- Customer certifies. The architect, owner or general contractor reviews the amount; missing backup sends the application back.
- Net payment applied. The customer pays the certified amount less retention under the contract’s payment terms; a pay-when-paid clause ties a subcontractor’s payment to the owner’s.
- Retention released. The held amount is paid after completion or acceptance, against the documents the contract names.
In the worked example, moving certification and payment from 30 to 45 days adds 27.4 days of DSO, because a second net bill is open at every month end.
In Germany, the same request is an Abschlagsrechnung. Under the civil code, the contractor may ask for a progress payment worth the work performed, documented in a statement that allows a quick and reliable assessment of it (BGB § 632a). Where a contract incorporates the VOB/B standard terms, § 16 sets when progress and final payments fall due, counted from receipt of the statement or the final invoice. The documentation therefore decides when the clock starts. The machine-builder view of the same mechanics, with down payments and acceptance, is in how machine builders collect down payments and retention.
Which DSO numbers should a contractor track?
Track four numbers instead of one: collectible DSO, retention days, unbilled days and days beyond terms, because each has a different owner and a different lever.
Four construction receivables metrics: formula, meaning and owner
On collectible DSO, EMCOR moves from 91 to 71 days and Comfort Systems from 103 to 83 days (our arithmetic from the filings above). On unbilled work, MasTec moves from 39 days on receivables alone to 90 days with contract assets.
Collectible DSO responds to billing discipline and follow-up, retention days to contract terms and releases, unbilled days to how fast finished work is billed. Calling retention a collections failure sends the wrong team after it. For the past-due view, see the AR aging report guide. For cases where DSO itself misleads, see when DSO misleads and which metric to use, and for the turnover view by industry, the accounts receivable turnover ratio.
How do you apply payments that arrive net of retention?
Apply a net payment to its pay application, keep the retention as its own open item with a release date, and never code the difference as a deduction.
Net payments break cash application in predictable ways: the remittance quotes a project or pay-application number instead of an invoice, the amount is the bill less retention, and one payment may cover several applications. A planned short payment should never open a dispute.
ERPs offer two standard ways to handle the difference. In SAP, a partial payment leaves the original receivable open and posts the payment with an invoice reference, while a residual item clears the original receivable and posts the outstanding difference as a new item on the customer account (SAP Help). Which one your retention uses depends on your configuration and reason codes. Either way, the retention must not land as on-account cash or as a deduction.
A monthly routine for contractors and suppliers to construction projects, in 6 steps
- Record the retention terms per contract: percentage, any cap, release trigger (substantial completion, acceptance or warranty end) and whether a bond replaces cash retention.
- Bill gross on the pay application or Abschlagsrechnung, with the backup the customer needs to certify it, and record the expected net amount and due date.
- When a payment arrives, apply it to the pay application it quotes, check that the shortfall equals the contractual retention, and book the difference as retention.
- Keep the retention as its own open item with a release date and a dunning block until then; chase the net balance as normal.
- Report the four numbers monthly: collectible DSO, retention days, unbilled days and days beyond terms, by project owner.
- Request the release before it is due, and attach the documents the contract names, such as the completion certificate, bond or acceptance record.
DocSense, the document understanding of Transformance, reads payment advices in any format with over 97% extraction accuracy across 100+ document types and 170+ languages, with no templates. ClearMatch reaches a 95% auto-match rate, runs end to end in under 8 minutes and validates 100% of postings; nothing posts without human sign-off (Transformance customer data, 2026).
For a payment that does not match, Vero, the AI agent of Transformance, investigates from Customer 360, fetches internal and external information to find more matches and proposes a match with the evidence attached. A person approves, and postings follow your approval thresholds. How an external system posts a payment and clears an item is in how payments post and clear open items from an external system.
Which part of construction DSO can you reduce?
Billing-cycle days are the part you can reduce: bill on the cut-off date, send complete backup, chase certification and the net balance, and request retention releases on time.
Every day a finished month waits for its pay application is a day of unbilled work, and an application returned for missing backup restarts certification. Track where each application sits with the reviewer, follow up on the net amount from its due date, and request each release when it falls due: retention that is due but not requested stays on the balance sheet.
CollectPulse actions 100% of overdue invoices within 24 hours, where manual teams reach 30-40%, and customers see DSO down 8-12 days on average (Transformance customer data, 2026). That is an average across customers, not a construction figure; retention stays a contract term. More levers are in how to reduce DSO.
What do the retention rules look like now?
Retention is a contract term that some laws now cap: New York voids construction-contract provisions requiring retainage above 5% of the contract sum, signed into law in December 2025.
The New York bill, S5655, amends the state’s General Business Law, was signed on 19 December 2025 and applies to contracts entered into on or after its effective date (New York State Senate, 2025). It is a 2025 law; we found no newer cap we could check against an official text.
In Germany, where a contract incorporates the VOB/B, § 17 sets how a cash retention is withheld and held and when a security for defects is returned; the contract sets the size of the security, and the contractor may replace one form of security with another, such as a bond. These are facts about the rules, not legal advice.
For the metric, a lower cap shrinks retention days on new contracts but not on the existing book, so DSO falls in steps as old projects close. A bond in place of cash retention removes the retention receivable: the customer pays the full certified amount.
Who Transformance is for
- ERP: SAP S/4HANA (on-premises, private or public cloud), SAP ECC, NetSuite, Microsoft Dynamics 365 Finance & Operations or Business Central, and Odoo, all running in production with customers; Oracle and Infor are supported.
- Size: mid-market to large enterprise, 250 to 2,000+ employees, including groups with several entities and shared service centers.
- Payment volume: from under 1,000 to over 100,000 payments a month.
- Industries: manufacturing, consumer goods and food and beverage, logistics, e-commerce, agriculture, energy and professional services.
- Scope: cash application alone, or the full order-to-cash: cash application, deductions, AR collections and cash forecasting.
Conclusion: three clocks in one number
Construction DSO is three clocks in one number: the billing and certification cycle, the retention held until completion, and the unbilled work some companies leave out. Retention is a contract term to track and release on time; billing-cycle days are what collections can move, and matching net payments fast, with a person approving every posting, clears that part sooner.
Key terms
- Days sales outstanding (DSO): receivables divided by revenue times the days in the period.
- Days beyond terms: how many days customers pay after the due date; the collections metric that leaves contractually held retention out.
- Payment terms: the agreed period and conditions for paying an invoice.
- Working capital: cash tied up in receivables, inventory and payables, including retention that is billed but not yet due.
- On-account cash: cash posted to a customer account without clearing a specific invoice; a payment net of retention should not end up here.
- Cash application: matching incoming payments to open invoices and clearing them in the ERP.
Related guides
- Which ERP systems does Transformance integrate with?
- When does DSO mislead, and which AR metric should you use instead?
- What is a good accounts receivable turnover ratio by industry?
- How machine builders collect down payments, milestones and retention
- DSO formula: how to calculate it, with examples and benchmarks
- How to automate cash application with AI
Frequently Asked Questions
What is a normal DSO in construction?
There is no official normal: German construction firms carry about 35 days of revenue in trade receivables (Deutsche Bundesbank, May 2026, data year 2023), while three large US contractors show 91 to 124 days including retainage (FY2025 10-K filings, February 2026). Compare on the same definition.
How do you exclude retention from DSO?
Subtract the retention receivable from total receivables, divide by revenue and multiply by 365, then report retention days as a separate figure. Some companies show retention on its own balance-sheet line, others disclose it in the notes.
Is retention a collections problem?
No, retention is a billed amount that the contract holds back until a release date, so it counts in DSO but not in days beyond terms. It becomes a collections task once the release is due and unpaid.
Does this apply to a business with 250 employees or one with 2,000 and several entities?
Yes, the split into collectible, retention and unbilled days works at any size. Transformance is built for mid-market to large enterprise, 250 to 2,000+ employees, including groups with several entities and shared service centers.
Which ERPs and payment volumes does Transformance cover?
Transformance covers from under 1,000 to over 100,000 payments a month and connects to SAP S/4HANA and SAP ECC, NetSuite, Microsoft Dynamics 365 Finance & Operations and Business Central, and Odoo, all in production with customers; Oracle and Infor are supported.
How long does it take to start and what does it cost?
The ERP connection typically takes 2-3 days, and your IT team may be involved; the full rollout takes up to 4-8 weeks. Cost depends on scope and the number of entities, from cash application alone to the full order-to-cash. Book a Call and we size it with you.
SAP, SAP S/4HANA, Microsoft, Dynamics 365, Business Central, Oracle, NetSuite, Odoo and Infor are trademarks of their respective owners (SAP SE, Microsoft Corporation, Oracle Corporation, Odoo S.A., Infor). Transformance is not affiliated with or endorsed by them.
