AdjudicationFAQs

Understanding Singapore's Building and Construction Industry Security of Payment Act

Introduction

Cash flow is the lifeblood of any construction project. Yet across Singapore’s building and construction industry, late payment has long been a persistent problem — one that ripples down from developers to main contractors, subcontractors, suppliers, and consultants alike. The Building and Construction Industry Security of Payment Act (commonly called the SOP Act) was enacted in 2005 to address this directly. It gives every party who performs construction work or supplies related goods and services a statutory right to be paid, and provides a fast, affordable mechanism — adjudication — to recover money that is wrongly withheld. This guide explains how the Act works, who it protects, and what you need to do — and avoid — to get the full benefit of its protections.

Why the Issue Matters in Singapore Projects

Construction projects involve long chains of parties. A developer engages a main contractor; the main contractor brings in subcontractors; subcontractors buy from suppliers and engage specialist trades. Money flows slowly down this chain, and disputes about how much is owed — or whether payment is due at all — are common.

Before the SOP Act, “pay when paid” clauses were widely used. Under such clauses, a main contractor could refuse to pay its subcontractors until it had received payment from the developer — even if the dispute had nothing to do with the subcontractor’s work. A subcontractor could complete its work on time and still wait months for payment.
The financial consequences are serious. Delayed payments force smaller companies to fund ongoing works from their own resources, creating pressure on cash reserves that can cause genuine insolvency. Project delays and chain-reaction disputes follow.

The SOP Act changes this. It voids “pay when paid” and “pay if paid” clauses outright, creates a statutory entitlement to progress payment, sets clear timelines, and provides a binding adjudication process that typically resolves disputes within weeks rather than years. By end-2018, the Act had already facilitated payments of nearly S$1 billion across the industry. Major amendments that took effect in December 2019 strengthened its reach further — expanding coverage, tightening response obligations, and improving the adjudication process.

Legal Framework

What the Act Covers

The SOP Act applies to written contracts for: (a) construction work carried out in Singapore; (b) consultancy services related to construction (including architectural, engineering and quantity surveying contracts); and (c) the supply of goods and materials for use in Singapore construction projects. It covers both private and public sector projects.

The Act also covers overseas fabrication of components for Singapore projects, and — where both parties are Singapore-registered — locally manufactured prefabricated components for overseas projects. If a consultant provides services from overseas to a Singapore project, they are covered.

Contract Clauses That Are Void

The following types of clauses are unenforceable under the SOP Act:

“Pay when paid” and “pay if paid” clauses — a party cannot make payment to a subcontractor conditional on first receiving payment from above.
Clauses that attempt to exclude or limit the Act’s operation (“contracting out”).
Clauses that deter a person from exercising their rights under the Act.
Provisions that limit interest on late progress payments below the prescribed minimum rate (currently 5.33% per annum, aligned to the Supreme Court judgment debt rate).

The Key Parties

Understanding who is who under the Act is important:

Claimant — the party who has performed work or supplied goods/services and is entitled to payment (e.g. a subcontractor claiming from a main contractor).
Respondent — the claimant’s immediate client; the party who must respond to a payment claim and make payment.
Principal — the respondent’s client (e.g. a developer who hired the main contractor). The principal plays a role if the respondent fails to pay after adjudication.
Adjudicator — an independent professional appointed by the Authorised Nominating Body to decide payment disputes.
Authorised Nominating Body (ANB) — currently the Singapore Mediation Centre (SMC), which administers the adjudication process and appoints adjudicators.

Key Principles and Common Scenarios

Step 1: Serving the Payment Claim

The process begins when the claimant serves a payment claim on the respondent. A payment claim must be in writing and must: identify the contract; state the claimed amount with reference to the period it covers; include sufficient detail to identify and describe each item claimed; and be supported by relevant documentation and calculations.

Timing matters. If the contract specifies a date or period for serving payment claims, follow it. If not, a claim may be served by the last day of any calendar month, and only one claim may be made per month. The claimant does not need to state that the claim is made under the SOP Act, but doing so adds clarity.

Who can claim? Main contractors from project owners; subcontractors from main contractors; sub-subcontractors from subcontractors; consultants; and suppliers of materials, plant, equipment or labour used on a construction site

Step 2: The Payment Response

Upon receiving a payment claim, the respondent must serve a payment response. This is required in all circumstances for construction contracts — regardless of whether the respondent agrees with the amount, disputes it entirely, or intends to pay nothing. Silence is not an option.

The payment response must: be in writing; identify the payment claim it relates to; state the amount the respondent proposes to pay (or “nil” if nothing); and include all reasons for withholding any money, with a breakdown of each item and supporting calculations. Any other objections to the payment claim must also be raised in a payment response.

This last point is critical: any reason for withholding payment or objections that is not raised in the payment response will be ignored by an adjudicator if the dispute goes further. Respondents who fail to flag a counterclaim, set-off or defect issue at this stage lose the right to raise it later.

Timelines: The respondent must respond within the contractual timeline, subject to a cap of 21 days from the date the payment claim is served. If the contract specifies no timeline, the default is 14 days.

Note that for pure supply contracts (where no on-site installation is involved), a formal payment response document is not required — but any reasons for withholding payment must still be communicated in writing to the claimant by the payment due date.

Step 3: The Dispute Settlement Period

If the claimant receives no payment response, or disputes the amount proposed in one, both parties enter a 7-day dispute settlement period that begins at the end of the payment response deadline. During this window, parties can negotiate and try to settle. The claimant cannot lodge an adjudication application during this period.

The respondent may still provide a payment response during this period (if none was given earlier), or may vary a payment response already given. Any settlement reached should be recorded in writing.

Step 4: Payment

If the payment response is accepted, payment must be made by the payment due date:

Construction contracts: within the contractual payment period, subject to a maximum of 35 days after the payment response due date or the date of the tax invoice. If no contractual due date is specified, payment is due within 14 days.
Pure supply contracts: within the contractual period, subject to a maximum of 60 days from the payment claim. If no date is specified, payment is due within 30 days.

Unpaid amounts accrue interest at the higher of the contractual rate or 5.33% per annum (the Supreme Court judgment debt rate). This interest entitlement arises automatically — the claimant does not need to separately claim it.

Step 5: Adjudication

If the dispute is not resolved by the end of the dispute settlement period, or if the respondent simply fails to pay an accepted amount, the claimant can apply for adjudication. Only the claimant can initiate this process.

Before filing, the claimant must serve a notice of intention to apply for adjudication on the respondent. The notice must include the project and contract details, the claimed amount, the response amount (if any), and a brief description of the dispute.

The adjudication application must then be filed with the SMC within 7 days. This is a hard deadline — missing it means losing the right to adjudicate that specific payment claim (though the unpaid amount can be rolled into the next payment claim)

Costs of Adjudication

ANB application fee: $600 (per application; $1,200 for a review application)

Adjudicator’s fee: capped at $2,400 for claims up to $24,000, or 10% of the claimed amount for claims exceeding $24,000. Rate not to exceed $2,400 per day / $300 per hour.

Fees may be shared between parties, but the adjudicator decides the proportion. Both parties may also incur their own professional costs (lawyers, consultants).

Once the application is filed, the SMC appoints an adjudicator within 7 days. The respondent then has 7 days to submit an adjudication response. Any response filed late will be disregarded by the adjudicator.

The adjudicator decides the matter within 7 to 14 days of the adjudication commencing. The adjudicator can have more time only if both parties agree. The determination is binding on both parties unless and until the dispute is finally resolved by a court, arbitration, or agreement.

If the Respondent Refuses to Pay After Adjudication

Four enforcement remedies are available under the Act:

Suspend work or supply: After giving at least 7 days’ written notice to the respondent, principal and owner, the claimant may stop work. During suspension, the claimant is not liable for resulting losses. Work must resume within 3 days of full payment.
Exercise a lien: The claimant may retain unfixed goods it has supplied to the site that have not been paid for, again after 7 days’ notice.
Enforce as a judgment debt: The adjudication determination can be enforced as a judgment with the approval of the court, allowing the claimant to pursue enforcement steps (e.g. garnishment, winding-up) directly.
Direct payment by the principal: If the main contractor fails to pay, the developer or other principal above the respondent may step in and pay the claimant directly, then recover that amount from the respondent.

Adjudication Review

A dissatisfied claimant or respondent may apply for a review of the adjudication determination if the disputed amount exceeds $100,000. The respondent must pay the adjudicated amount into a trust account held by the SMC before it can seek a review. The review is conducted by a fresh adjudicator (or a panel of three if the disputed sum exceeds $1 million) and must be decided within 14 days unless parties agree to an extension.

Practical Examples

Example 1: Subcontractor Not Paid by Main Contractor

XYZ Subcontractors completes its structural works and serves a payment claim on the main contractor on 31 July. The contract allows the main contractor 21 calendar days to respond — deadline: 21 August. The main contractor serves a payment response on 21 August acknowledging only half the claimed amount, without reasons.

XYZ disputes the response. The dispute settlement period runs until 29 August. No settlement is reached. XYZ serves a notice of intention to adjudicate and lodges an adjudication application with the SMC by 5 September (within the 7-day window). The SMC appoints an adjudicator within 7 days. The adjudicator determines the matter within 14 days. The main contractor fails to pay the adjudicated amount. XYZ obtains the High Court’s approval to enforce the adjudicated amount as a judgment debt and begins enforcement.

Example 2: "Pay When Paid" Clause

A subcontract states: “The main contractor will pay the subcontractor within 7 days of receiving payment from the employer.” Under the SOP Act, this clause is void. The subcontractor’s right to payment is independent of whether the main contractor has been paid by the project owner. The statutory timelines apply, and the subcontractor may claim and adjudicate regardless of what is happening in the main contract.

Example 3: Respondent Ignores the Payment Claim

A main contractor receives a payment claim from a sub-contractor but neither pays nor provides a payment response. After the 14-day response deadline and the 7-day dispute settlement period pass without resolution, the sub-contractor serves a notice of intention to adjudicate and lodges an adjudication application with the SMC. Because the respondent gave neither a payment response nor an adjudication response, the adjudicator is required to make a determination within just 7 days.

Common Mistakes

Mistakes Made by Claimants

Missing the 7-day window to file the adjudication application. This is the most costly error — once the window closes, the right to adjudicate that specific claim is lost. The unpaid amount may be rolled into the next payment claim, but momentum and leverage are lost.
Serving an invalid payment claim. A claim without sufficient detail, without the required documentation, or served on the wrong party may be invalid, potentially undermining an adjudication application built on it.
Failing to serve the notice of intention before filing. The notice is a mandatory prerequisite — filing without it makes the adjudication application defective.
Claiming work done more than 30 months ago. Such claims are time-barred under the Act.

Mistakes Made by Respondents

Not responding at all. In construction contracts, serving a payment response is critical. A respondent who gives no payment response generally cannot raise any objection — including legitimate ones — in adjudication.
Raising new objections in the adjudication response. Any reason for withholding payment or objections to the claim must have been communicated to the claimant in the payment response. Objections introduced for the first time in the adjudication response will be disregarded by the adjudicator.
Believing “pay when paid” clauses offer protection. They do not — they are void under the Act.
Missing the 7-day adjudication response deadline. A late response will be disregarded, leaving the adjudicator with only the claimant’s case.

Mistakes Made by Both Parties

Not having a written contract. The SOP Act only applies to written contracts or the written portions of contracts. Purely oral agreements fall outside its protection.
Failing to keep contemporaneous records. Adjudications are decided quickly and largely on documents. Site records, correspondence, photographs, and signed delivery orders are your evidence.

Practical Steps and Checklist

If You Are a Claimant

Confirm your contract is in writing and that the work or supply is covered by the SOP Act.
Check the contract for the specified payment claim date. If none, serve by the last day of the relevant calendar month.
Ensure your payment claim is valid: in writing, identifies the contract, states the amount with a clear breakdown, and is supported by relevant documentation.
Diarise the deadline for the payment response (14 days statutory; up to 21 days if the contract specifies).
If the response is disputed or not received, note when the 7-day dispute settlement period ends.
If unresolved: immediately serve a notice of intention to adjudicate on the respondent.
File your adjudication application with the SMC within 7 days of the trigger event.
Keep your application clear and focused. Adjudicators decide quickly; clarity wins.

If You Are a Respondent

Diarise the payment response deadline as soon as you receive a payment claim.
Always serve a payment response — even if you agree with the full amount claimed.
In your response, include every reason you have for withholding or reducing payment. You will not be allowed to add new reasons later.
If you receive an adjudication application, respond within 7 days.
Pay the adjudicated amount within the time directed by the adjudicator – usually within 7 days of receiving the determination.
If you wish to seek an adjudication review (dispute over $100,000 and there is a payment response issued), pay the adjudicated amount into the SMC trust account first.

For All Parties

Never include “pay when paid” or “pay if paid” clauses in your contracts. They are void and using them simply invites claims.
Keep contemporaneous records: payment claims, payment responses, delivery orders, site progress records, emails and correspondence.
Know your timelines. Every step in the SOP Act process has a strict deadline. A diary system is essential.
Seek legal advice early. The SOP Act is procedurally demanding; getting advice at the payment claim stage, rather than after a determination has gone against you, costs far less.

Conclusion

Singapore’s SOP Act is one of the most practical tools available to anyone working in the building and construction industry. It gives you a legal right to be paid, a fast mechanism to recover money owed, and real consequences for parties who ignore their obligations. But it is also time-sensitive and unforgiving. The window to act is often just seven days, and procedural errors — a late filing, an omission from a payment response — can cost you the right to pursue a legitimate claim.

Whether you are a developer, main contractor, subcontractor, supplier or consultant, understanding the SOP Act — and having systems in place to observe its deadlines — is not optional. It is part of doing business in Singapore’s construction sector.

Need help with a Payment Dispute or Contract Review?

Our team advises contractors, subcontractors, suppliers and developers on all aspects of the SOP Act — from structuring payment claim processes, to adjudication applications and enforcement. If you have a payment issue on a Singapore construction project, contact us to discuss your position.

Disclaimer: This article is intended for general information only and does not constitute legal advice. The law described reflects the SOP Act as amended with effect from 15 December 2019. For advice specific to your situation, please consult a qualified lawyer.