Retention Payments Explained

Quick Answer: A retention payment is a percentage of the contract value (typically 3–5% on commercial work, 2.5% on JCT domestic) withheld by the client until the contractor has remedied any defects identified during a defects liability period (typically 12 months). Half is released at practical completion, the remainder at the end of the defects period. Retention is contractual, not statutory — it only applies if the contract specifies it. Under the Construction Act 1996, retention monies must be released without unreasonable delay and any contract that allows arbitrary withholding is unenforceable.

Summary

Retention is one of the few aspects of construction contracts that punishes contractors disproportionately. The principle — keep some money back so the client has leverage to get defects fixed — is sensible. The practice is often abused. Retention monies are routinely paid late, withheld for trivial or invented defects, lost when clients become insolvent, or simply never released because the contractor moves on and stops chasing.

For tradespeople running their own contracts, three distinct contexts matter. Commercial work under JCT or NEC contracts has standardised retention provisions and typically uses 3–5% retention with 12-month defects liability. Domestic work under contract uses lighter provisions; JCT Domestic Building Contracts use 2.5%. Domestic work without formal contract typically does not include retention at all — the client makes a final payment on completion and the trade addresses any defects under the implied warranty of the Consumer Rights Act 2015.

The Construction Act 1996 (Housing Grants, Construction and Regeneration Act, as amended by the Local Democracy, Economic Development and Construction Act 2009) regulates payment in construction contracts. Retention, as a payment mechanism, falls within its scope. Contracts must specify when retention is due, what triggers release, and what happens on insolvency. Provisions that conflict with the Act are void.

The practical reality for a small contractor is that retention often becomes a working capital problem. On a £200,000 commercial fit-out with 5% retention, £10,000 is held for 12+ months. If the contractor's bank has lent on the basis of receivables, the retention sits outside the funding pool. Retention bonds and project bank accounts are mechanisms that mitigate this; both are increasingly common on tier-1 main-contractor projects but rare on smaller work.

Key Facts

Quick Reference Table

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Contract type Typical retention Release at PC Release at end of defects Defects period
JCT SBC/Q (commercial) 3–5% 50% 50% 12 months
JCT D&B (commercial) 3–5% 50% 50% 12 months
JCT IC / ICD (intermediate) 3% 50% 50% 6–12 months
JCT Minor Works 5% 50% 50% 6 months
JCT DBC (Domestic Building) 2.5% 50% 50% 6 months
NEC4 ECC Option X16 retention 3–5% 50% 50% 12 months (defects date + period)
FIDIC Red Book 5–10% 50% 50% 12 months
Domestic without formal contract 0% (typically) n/a n/a n/a

Detailed Guidance

How Retention Is Calculated

Retention is calculated on each interim payment certificate. For a £200,000 contract with 3% retention and monthly interim payments:

This continues each month until practical completion. At PC, the total retention held is £6,000 (3% of £200,000). Half (£3,000) is released, leaving £3,000 held against defects liability. At end of defects period and issue of the Making Good Certificate, the remaining £3,000 is released.

The retention is calculated on certified value, not invoiced value. If a £30,000 invoice is certified at £25,000 (because the contract administrator disputes some items), retention is calculated on the £25,000.

Practical Completion (PC) — When and How Defined

Practical completion is the moment the project enters the defects liability period. The definition matters because it triggers half-retention release, the start of insurance transfer to the client, and the end of the contractor's right to suspend for non-payment.

Under JCT contracts, PC is defined as the date on which the contract administrator certifies the works are practically complete. This is the contract administrator's judgement. The works do not need to be perfect; minor snagging items (e.g. final paint touch-ups, end-of-job cleaning) can remain as long as they do not prevent the client occupying or using the building.

Disputes over PC certification are common. If the contract administrator refuses to certify PC despite the works being substantially complete, the contractor's recourse is statutory adjudication under HGCRA 1996. A notice of intention to refer to adjudication, properly served, normally produces a quick negotiated settlement.

Defects Liability Period — What Happens

During the defects liability period (DLP, sometimes called the rectification period), the contractor remains responsible for rectifying defects identified by the client. The mechanics:

  1. Client identifies a defect; notifies the contract administrator (or the contractor on direct contracts)
  2. Contract administrator issues a defects schedule
  3. Contractor has reasonable period to rectify (typically 14–28 days)
  4. Contractor returns to site, rectifies, notifies the contract administrator
  5. Contract administrator inspects and certifies the rectification

At end of DLP, the contract administrator issues the Making Good Certificate (or NEC4 Defects Certificate) if all notified defects have been rectified. Final retention is released.

Defects in the contractor's responsibility are those caused by failure to follow the specification or by defective workmanship. They do not include damage caused by the client (e.g. someone driving into a wall during occupation), wear and tear (e.g. carpet wearing in high-traffic areas), or defects in design that were the architect's responsibility.

Disputes over what is a "defect" are common. Items that are aesthetic preferences (paint colour shade, exact tile alignment within tolerance) are not defects. Items that fail the specification (paint not matching the specified colour, tile lipping outside the BS 5385 tolerance) are defects. The contract administrator adjudicates.

Project Bank Accounts (PBAs)

A PBA is a trust account jointly operated by the client, main contractor, and (typically) tier-2 subcontractors. Payments certified by the contract administrator flow into the PBA and are paid out to the named beneficiaries. Retention may be held in the PBA in a separate sub-account.

The PBA mechanism protects subcontractors against main contractor insolvency — the funds in the PBA are held in trust and are not available to the main contractor's insolvency practitioner. The Cabinet Office mandates PBA use on most central government construction contracts; many local authorities and large private clients also use them.

For a small contractor, being named as a beneficiary of a PBA on a tier-1 project is a significant protection. The administrative effort of setting up the PBA falls on the main contractor; the small contractor benefits without administrative burden.

Retention Bonds

A retention bond is a third-party guarantee (issued by a bank or specialist surety) that replaces the cash retention. The contractor pays a premium (typically 0.5–1.5% per annum of the bonded amount); the surety underwrites the client against defect claims. The contractor is paid the full certified value; if a defect arises and the contractor fails to rectify, the client claims on the bond.

For the contractor, a bond converts a working-capital problem into a small premium expense. For the client, the bond gives the same protection as cash retention but transfers the credit risk to the surety. Bonds are increasingly common on commercial work over £500,000; less common below.

Recovering Late or Withheld Retention

The most common retention dispute is the client refusing to release retention at the end of the defects period — either claiming defects that the contractor disputes, or simply going silent. The recovery sequence:

  1. Issue a payment notice under the contract or HGCRA 1996. The notice specifies the amount due (the retention release) and the basis. The client must respond with a "pay less notice" if they intend to withhold.
  2. If no pay less notice, the amount becomes due. Failure to pay by the final date entitles the contractor to suspend, claim interest, and refer the dispute.
  3. Statutory adjudication under HGCRA 1996 if dispute persists. The adjudicator decides within 28 days; their decision is binding pending arbitration or court.
  4. Court / Insolvency procedures if the client refuses to pay an adjudication award.

Most retention disputes settle at step 1 or 2. The HGCRA payment notice mechanism is well-understood; clients who try to withhold without a valid pay less notice almost always concede when adjudication is threatened.

Frequently Asked Questions

Should I include retention in a domestic quote?

Generally no. Retention is appropriate where there is a substantial defects risk and a long-running relationship between contractor and client (commercial fit-out, construction projects, public sector work). For a typical £5,000–£20,000 domestic kitchen, bathroom, or extension, retention adds administrative burden disproportionate to the benefit and is rarely a homeowner request. Use a final-payment-on-completion structure instead, with the homeowner protected by the Consumer Rights Act 2015 and the contractor's insurance. See standard payment terms for domestic and commercial work for typical payment structures.

Can I refuse retention on a commercial contract?

You can negotiate. Replacing cash retention with a retention bond is the most common alternative; the client is protected, you receive full payment, and the bond cost is a small premium. Some clients refuse to use bonds, in which case the cash retention is part of the contract terms. Pricing the cost of capital tied up in retention into your tender is reasonable practice on long-running contracts.

How long can retention be withheld?

Retention is held until the Making Good Certificate is issued (or equivalent), typically at the end of the defects liability period. If the client does not certify the Making Good Certificate when defects are remedied, the contractor can refer the dispute to adjudication. Retention "lost in time" is a common contractor problem; the discipline of chasing release at the precise end-of-DLP date prevents this.

What happens to retention if the client goes insolvent?

If the retention is held by the client (cash retention), it becomes part of the client's general assets in the insolvency. The contractor is an unsecured creditor for the retention amount and typically recovers very little (5–20p in the pound). If the retention is in a Project Bank Account, the funds are protected as a trust. If a retention bond replaces cash, the contractor was paid in full and there is no exposure. The case for PBA or retention bond is strongest on contracts over £500,000 with longer DLPs.

Can I claim interest on late retention?

Yes, under the Late Payment of Commercial Debts (Interest) Act 1998. The statutory rate is the Bank of England base rate plus 8%, and a fixed compensation payment of £40 (small debts) to £100 (large debts) is also available. Many contracts include their own interest clauses; if not, the statutory rate applies by default. See the payment-chasing procedure for late commercial debts for full procedure.

Regulations & Standards