Understanding retention payments in UK construction contracts

If you work in the UK construction industry, you’ll be painfully familiar with retention payments. For those new to the sector, it can be a nasty surprise: you complete the work, issue your invoice, and the client only pays 95% of it. That withheld slice, known as retention, is a standard feature of UK construction contracts, designed as a form of security for the client. But for the subcontractor, it's a major cause of cash flow headaches, administrative nightmares, and financial risk.

This article explains exactly what retention money is, why it's used, the two-stage process for getting it released, and the practical steps you can take to recover it. We’ll break down the jargon and give you a clear roadmap for chasing what you're owed, months or even years after the scaffolding has come down.

What Are Retention Payments in UK Construction?

A retention is a sum of money withheld from a payment due to a contractor or subcontractor. In a typical UK construction project, the client (or main contractor) will hold back a percentage of every interim or final payment made to their supply chain. This money is held as a safeguard to ensure the contractor completes the project to the specified standard and rectifies any defects that may appear after completion.

The key details are:

• The Percentage: The amount held is usually between 3% and 5% of the total contract value. 5% is very common.
• The Purpose: It acts as an incentive for the contractor to return to the site to fix any problems that emerge during a set period after the main work is finished. This is known as the Defects Liability Period.
• The Legal Basis: The right to deduct retention must be clearly stated in the construction contract. It's a standard clause in most industry contracts, such as those from the Joint Contracts Tribunal (JCT) or the NEC (New Engineering Contract) suite.

Think of it as the client's insurance policy, funded by you. They hold onto a portion of your earnings to cover the potential cost of hiring someone else to fix your work if you fail to do so yourself. While the logic is understandable from the client's perspective, for the subcontractor, it means a significant chunk of their revenue is locked up, often for more than a year, severely impacting cash flow.

The Two-Stage Retention Release Process

Getting your retention money back isn't a single event. It’s a formal, two-part process tied to specific project milestones. Understanding this timeline is the first step to successfully recovering your funds. The entire process is typically managed by a "contract administrator" – usually the project's architect, engineer, or surveyor – who acts as an intermediary and certifies when milestones have been met.

Stage 1: Practical Completion and the First Release

The first key milestone is "Practical Completion," or PC. This is a crucial term in construction contracts.

What is Practical Completion? Practical Completion is the point at which the project is declared finished, allowing the client to take possession and use the building or works for its intended purpose. It does not mean the work is perfect; there may still be minor outstanding items or snags (a "snagging list") that don't prevent the client from moving in.

Once the contract administrator is satisfied that the work has reached this stage, they will issue a Certificate of Practical Completion. This certificate is the official trigger for two things:

1. The start of the Defects Liability Period.
2. The release of the first half of the retention.

At this point, you are entitled to invoice for 50% of the total money that has been held back. For example, if the total retention held is £10,000 (e.g., 5% of a £200,000 job), you can now claim the first £5,000.

Stage 2: The Defects Liability Period and the Final Release

After Practical Completion, the project enters the Defects Liability Period (DLP), also known as the "rectification period".

What is the Defects Liability Period? This is a fixed period, typically 12 months, during which the contractor is obliged to return to the site and fix any defects that become apparent through normal use. These are "latent defects" – problems that weren't obvious at the time of Practical Completion, such as a leaking roof that only shows up during heavy rain, or a heating system that fails in winter.

The process at the end of the DLP works as follows:

1. Final Inspection: Towards the end of the 12-month period, the contract administrator will inspect the works again.
2. Schedule of Defects: If any defects covered by the contract have arisen, the administrator will issue a "Schedule of Defects," listing the items that need to be fixed. The contractor is then given a reasonable period to "make good" these defects at their own cost.
3. Certificate of Making Good: Once the contractor has rectified all the items on the schedule (or if no defects were found in the first place), the contract administrator will issue a Certificate of Making Good Defects.

This final certificate is the trigger for the release of the second and final portion of the retention. You can now invoice for the remaining 50% of the money held.

Here is a typical timeline for a project with a 5% retention and a 12-month DLP:

Project Phase	Key Milestone / Action	Retention Status
During Construction	Interim payments are made for work completed.	5% is deducted from each payment.
Project End	Work is finished.	Total retention held is 5% of the contract value.
Practical Completion	Contract administrator issues the Certificate of Practical Completion.	The Defects Liability Period (e.g., 12 months) begins.
First Release	Subcontractor invoices for the first half of the retention.	50% of the total retention is released (e.g., 2.5% of contract value).
Defects Liability Period	12 months pass. Client uses the building.	Remaining 2.5% is still held by the client.
End of DLP	Contract administrator inspects for defects.	Contractor is instructed to "make good" any defects found.
Making Good	Contractor fixes all items on the Schedule of Defects.	Work is signed off by the contract administrator.
Final Release	Contract administrator issues the Certificate of Making Good Defects.	Subcontractor invoices for the final half of the retention.
Final Payment	Client pays the remaining retention.	100% of retention is now paid.

Why Do Retention Payments Cause So Many Problems?

On paper, the system seems logical. In practice, it's a source of constant friction and financial distress for subcontractors.

• Severe Cash Flow Impact: For a small business, having 3-5% of your revenue from every single job tied up for over a year is crippling. It's working capital that you can't use to pay staff, buy materials for the next job, or invest in your business. You've incurred all the costs of the job, but you're not fully paid for it.
• Administrative Hell: Tracking different retention amounts across dozens of projects, all with different PC dates and DLP end dates, is a huge administrative burden. It’s easy for a final release date to be missed, especially in a busy office.
• Insolvency Risk: This is the biggest danger. The retention money is typically held in the main contractor's or client's general bank account. It is not ring-fenced in a protected trust account. If the party holding your money goes insolvent before your retention is released, your money is gone. You become just another unsecured creditor at the back of a very long queue, with little to no chance of recovery. Billions of pounds in retention payments are estimated to be lost to upstream insolvencies in the UK construction sector.
• Disputes and Excuses: The end of the DLP often becomes a battleground. Clients may try to argue that issues are "defects" when they are actually "snagging" that should have been dealt with before PC, or simply damage and wear and tear caused by their own use. Some less scrupulous firms use the retention as a final, unjustified negotiating tool to chip away at the final account.
• Deliberate Non-Payment: Often, the final 2.5% is simply "forgotten" about. The amount can be small enough (£1,000-£5,000) that the main contractor knows it may not be economical for the subcontractor to launch formal legal proceedings to recover it. They rely on the subcontractor giving up, and sadly, many do.

A Practical Checklist for Getting Your Retention Released

You can't always avoid retentions, but you can be systematic and proactive to maximise your chances of getting paid in full and on time.

Before You Sign the Contract

• Read the Clauses: Scrutinise the retention and payment clauses. What is the percentage? What is the length of the Defects Liability Period? Who is the contract administrator?
• Negotiate: Don't be afraid to negotiate. If you're a valuable subcontractor, you may be able to get the percentage reduced (e.g., from 5% to 3%), or the DLP shortened (e.g., from 12 months to 6).
• Ask About Protection: Ask if the retention will be held in a separate trust account. The answer will almost certainly be no, but asking the question signals that you are on top of your finances and expect to be paid.

During the Project

• Invoice Clearly: Your applications for payment and VAT invoices should be crystal clear. Show the gross value of the work, the retention being deducted, and the net amount due for payment. This creates a clear paper trail of how much is being held.
• Keep Meticulous Records: Keep copies of all correspondence, site instructions, and meeting notes. Most importantly, ensure you have a diary system for key dates.

At Practical Completion (First Release)

• Get the Certificate: As soon as you believe the project is practically complete, chase the contract administrator for the Certificate of Practical Completion. Do not let this drift.
• Invoice Immediately: The day you receive the certificate, raise your application for payment or VAT invoice for the first half of the retention. Reference the certificate in your invoice.
• Diarise the DLP End Date: As soon as PC is certified, put the DLP end date in your calendar with a reminder set for one month before.

At the End of the Defects Liability Period (Final Release)

• Be Proactive: Do not wait for the client or contract administrator to contact you. One month before the DLP ends, write to them to remind them the period is expiring and request a final inspection.
• Address Defects Promptly: If a Schedule of Defects is issued, deal with the legitimate items quickly. Document your work and inform the administrator as soon as you are finished.
• Chase the Final Certificate: Once the defects are made good, relentlessly (but politely) chase the contract administrator for the Certificate of Making Good Defects. This is your golden ticket.
• Invoice Immediately (Again): The moment you have the final certificate, issue your invoice for the final retention amount.

Chasing the Overdue Retention Payment

If the due date for the retention release passes and you haven't been paid, you must switch into credit control mode.

• Treat It Like Any Other Debt: A contractually due retention payment is no different from any other unpaid invoice. The same principles of credit control apply: a sequence of polite reminders, followed by firmer warnings.
• Automate the Follow-Up: This is where technology can be a lifesaver. Manually tracking dates that are 12-18 months in the future is prone to error. You can use an invoice chasing system to schedule reminders far in advance. For example, in a tool like InvoiceReminder, you could set up a custom chase schedule to automatically start sending emails the day after the final retention is due, ensuring it never gets forgotten.
• Add Statutory Interest: Under the Late Payment of Commercial Debts (Interest) Act 1998, you are entitled to add interest to a late retention payment once it is due. The rate is 8% plus the Bank of England's base rate. You can also claim a fixed compensation sum (£40, £70, or £100 depending on the debt size). Mentioning this in your chase emails often focuses the mind.
• Formal Action: If reminders fail, your options are the same as for any commercial debt. You can send a formal Letter Before Action, and then escalate to either Adjudication (a fast-track dispute resolution process specific to construction) or the Small Claims Court.

The Legal Landscape and Future of Retentions

The practice of holding retentions is governed by the Housing Grants, Construction and Regeneration Act 1996 (often called the "Construction Act"). A key protection is that if a client wants to pay less than the amount due (which includes a retention release), they must issue a valid "Pay Less Notice" before the final date for payment. This notice must specify the sum they consider to be due and the basis on which that sum is calculated. If they fail to issue a valid notice in time, they are generally obliged to pay the full amount stated in your application.

There has been a long-running industry campaign to reform or abolish the cash retention system due to the problems it causes, particularly the risk of insolvency. The collapse of major contractors like Carillion in 2018 highlighted the issue, as tens of thousands of subcontractors lost their retention money overnight.

A private members' bill, known as the "Aldous Bill," has been put before Parliament several times, proposing that all cash retentions be held in a government-approved deposit protection scheme, similar to how tenancy deposits are handled. This would protect the money from upstream insolvency. While the bill has strong cross-party support, it has not yet become law. For now, the old system remains, and subcontractors must remain vigilant.

Frequently asked questions

What is a typical retention percentage in the UK?

The most common retention percentage in UK construction contracts is 5% of the value of the works. This is often structured so that the effective rate reduces to 2.5% after Practical Completion, with the final 2.5% being released at the end of the Defects Liability Period. While 3% is sometimes seen, 5% remains the default for many main contractors.

Can a client hold my retention money forever?

No. The contract must specify the conditions for the release of the retention (e.g., the issuing of the Certificate of Making Good Defects). Once these contractual conditions are met, the retention becomes due for payment. If the client or contractor fails to pay it, it becomes a simple debt which you can pursue through adjudication or the courts, just like any other unpaid invoice.

Is VAT charged on the retention amount?

Yes, and this is a critical cash flow point. Under HMRC rules, VAT is due on the full value of the work you have done at the time you issue your VAT invoice (the "tax point"). This means you must declare and pay the VAT on the 100% value of the work, even though you have only received 95% of the payment. You effectively fund the VAT on the retention amount from your own pocket until it is finally released.

What happens to my retention if the main contractor goes insolvent?

In most cases, you will lose it. Because retention money is rarely held in a separate, protected trust account, it is treated as part of the insolvent company's general assets. As a subcontractor, you will be classed as an "unsecured creditor," placing you far down the list for any potential payout. The chances of recovering retention from an insolvent company are extremely low.

Can I charge interest on a late retention payment?

Yes. Once the retention payment is contractually due and remains unpaid, it is considered a late commercial debt. Under the Late Payment of Commercial Debts (Interest) Act 1998, you have a statutory right to claim interest at 8% above the Bank of England base rate, plus a fixed compensation fee.

What is a 'pay less' notice in relation to retention?

A pay less notice is a formal notice that a payer (client or main contractor) must issue if they intend to pay less than the sum due in a payment application, which includes an application for the release of retention. The notice must be given in time and must set out the amount they believe is due and the detailed calculation behind it. If they fail to issue a valid pay less notice, they are legally obliged to pay the amount you have applied for.

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