Subcontractor Final Account in Construction: How to Agree It

A subcontractor final account is the definitive reconciliation of everything a subcontractor is owed under its subcontract, once the works are complete: the original subcontract sum, every agreed and disputed variation, loss and expense claims, contra charges, and retention. Getting it agreed cleanly - rather than left to drag on for months - is one of the more underrated skills a commercial manager or QS can bring to a project.

For the subcontractor, the final account is the last major cash event on the job, including the release of retention that may have been held for a year or more. For the main contractor, it closes off financial exposure on that package and feeds directly into their own final account with the client. Get it wrong, and the numbers you carry forward - and the disputes you inherit - follow you upstream.

This guide sets out exactly what a subcontractor final account needs to contain, the documents required to support it, how to reconcile variations, claims and retention without it turning into a stand-off, and where the timing sits relative to the main contractor's own account. It closes with a worked example showing how a subcontract sum typically moves from contract value to agreed final figure.

Whether you're assessing accounts submitted by subcontractors, or preparing one to submit yourself, the same discipline applies: document everything, reconcile early, and don't let unresolved items sit until the final meeting.

What Is a Subcontractor Final Account and Why Does It Matter?

Every subcontract starts with an agreed subcontract sum, priced against a scope of works, drawings and specifications at the point of order. Almost nothing on a live construction project stays exactly as tendered: instructions change scope, provisional sums get remeasured against as-built quantities, delays generate loss and expense claims, and defects or attendance issues generate contra charges in the other direction. The final account is the single document that reconciles all of that movement into one number both parties can sign off.

Subcontractor Final Account vs Main Contract Final Account

It's worth being precise about which final account is which. The main contractor has its own final account with the client (or contract administrator), covering the whole project. Sitting beneath that, each subcontractor has its own final account with the main contractor, covering only its package. The two are connected - a subcontractor's agreed variation often needs to be recovered through the main contractor's own account upstream - but they are legally and procedurally separate documents, usually governed by different sets of contract terms.

Why It Matters

For the subcontractor, the final account determines the last significant payment on the job and triggers release of retention that may have been withheld since practical completion of their works. For the main contractor's commercial team, a properly agreed subcontractor final account protects margin, provides the evidence needed to pass entitled costs up through the main contract, and closes down the risk of a late-stage adjudication or dispute. A sloppy or rushed subcontract final account is one of the most common sources of cash flow disputes on UK projects.

• The agreed original subcontract sum, as ordered
• Variations and instructed changes, priced against agreed rates or fair valuation
• Remeasurement of provisional sums or remeasurable work against as-built quantities
• Loss and expense or claims arising from delay, disruption or late information
• Contra charges for defects, attendance, damage or programme non-compliance
• Retention held and due for release once the defects liability period has expired

Documents Required From the Subcontractor

A final account submission stands or falls on the quality of the documents behind it. Site records, logs of variations including agreed quotations, invoices, proof of payments and any other necessary backup to evidence the value of the works undertaken should accompany the submission, together with copies of all relevant instructions, quotation submissions and acceptances. Where a claim for extension of time or loss and expense is included, the supporting records need to show cause and effect, not just an assertion of entitlement.

The contractor's QS should cross-check every item against its own site diary, instruction register and payment history before accepting the subcontractor's figures. Where documents are missing - a signed daywork sheet, an instruction reference, a measurement record - flag the gap immediately rather than at the final account meeting. Chasing paperwork late in the process is the single biggest cause of delay in getting subcontract accounts closed out.

Reconciling Variations, Claims and Retention

Variations

Every variation in the final account needs to trace back to a written instruction, or a confirmation of an instruction given verbally on site. Valuation should follow the subcontract's own valuation rules - usually contract rates first, then a fair rate where the work is not of similar character, then daywork only where measurement genuinely isn't practical. The net amount for every variance should be shown separately rather than bundled into a single adjustment figure, so both parties can see exactly what is agreed and what remains open.

Loss and Expense and Other Claims

Claims for prolongation, disruption or additional preliminaries need contemporaneous evidence: the instruction or event that caused the loss, the period affected, and the actual cost incurred - not a percentage uplift applied without substantiation. Assess the sum claimed versus the sum considered payable, and list the reasons for any difference in accordance with the contract, so the subcontractor has something concrete to respond to rather than a single reduced total.

Retention

Most UK subcontracts hold retention at 3-5% of interim valuations, released in two tranches: half at practical completion of the subcontract works, and the remainder at the end of the defects liability period, once outstanding defects are made good. The final account should show retention held, retention already released, and what remains due, clearly separated from the trade balance so the subcontractor can see the defects liability period has genuinely expired before the final tranche is claimed.

• Match every variation to a written instruction or confirmed verbal instruction
• Separate agreed items from disputed items - never bundle them into one net figure
• Require contemporaneous records for any loss and expense or disruption claim
• Track retention in two tranches and confirm the defects liability period end date
• Deduct contra charges only where they are separately evidenced and were notified at the time

Agreeing the Account: The Negotiation Process

Once the subcontractor's submission and the contractor's assessment both exist, the gap between them needs closing through a structured negotiation, not an email chain that runs for months. Standard form subcontracts often contain provisions that set specific timeframes within which the process must be undertaken, so it's worth checking the relevant clause before assuming there's no deadline pressure - there usually is one, on both sides.

It is good practice to organise and attend a dedicated final account meeting, with the appropriate personnel from both parties present, to work through disputed items line by line rather than in writing. Many contractors and subcontractors run these discussions on a without prejudice basis, so figures can be tested and moved without either side being bound by an opening position. Once agreement is reached, get it signed as being in full and final settlement before the final payment is released - this is what actually closes the account and prevents items resurfacing later.

Timing: Subcontract Final Account vs the Main Contractor's Own Final Account

Subcontract final accounts and the main contractor's own final account with the client are separate exercises, but they are rarely independent in practice. A main contractor generally wants subcontract accounts agreed - or at least well understood - before finalising its own account upstream, because entitlements the subcontractor is claiming (an extension of time, a loss and expense sum, a disputed variation) often need to be recovered through the equivalent mechanism in the main contract. Agreeing the subcontract account too early, before the position with the client is clear, can mean settling on terms the contractor can't fully recover.

Equally, sitting on a subcontract final account until the main contract account is settled creates its own risk: subcontractors are entitled to be paid within the timeframes set out in their own subcontract, regardless of what is happening on the main contract, and the Construction Act's payment provisions apply independently at each contractual tier. The practical approach most commercial teams take is to agree the subcontract account's substance - the variations, the measurement, the claims - as early as possible, while keeping final sign-off flexible enough to reflect any late movement on the main contract that directly affects that package.

Common Disputes in Subcontractor Final Accounts

Most subcontract final account disputes come down to a small number of recurring issues, and almost all of them are preventable with better records kept during the project rather than reconstructed after the fact.

• Missing or unsigned instructions - variations claimed with no paper trail back to an authorised change
• Disputed rates for work outside the original scope, where contract rates don't clearly apply
• Loss and expense claims submitted as a lump sum with no contemporaneous cause-and-effect evidence
• Contra charges raised late, after the event, with no notice given to the subcontractor at the time
• Retention withheld beyond the agreed defects liability period without a clear reason
• Time-barred claims - a party disputes an assessment after the contractual deadline for doing so has passed

That last point is worth flagging on its own. If you receive a final account assessment you don't agree with, it is essential to dispute it within the period stated in the subcontract, or you risk being time-barred from raising it later, however strong the underlying case. Where a dispute can't be resolved through the final account meeting, most UK subcontracts preserve the right to adjudication, which remains the fastest formal route to a binding decision if negotiation genuinely stalls.

Worked Example: Structuring a Subcontract Final Account

The example below shows how a straightforward single-trade subcontract - originally valued at £480,000 - moves to an agreed final account figure once variations, loss and expense and contra charges are reconciled, and how that compares against payments already made to arrive at the balance due.

Setting the account out this way - starting sum, then each adjustment shown separately, then payments to date, then balance due - makes it far easier for both parties to see exactly where the number comes from. It's also the format most likely to survive scrutiny if the figures are later checked against the main contractor's own account with the client, or tested in adjudication.

Frequently Asked Questions

What is a subcontractor final account?

A subcontractor final account is the agreed total sum due to a subcontractor once its works are complete, reconciling the original subcontract sum against variations, remeasurement, loss and expense claims, contra charges and retention into a single, signed-off figure.

How long does a subcontractor have to submit a final account?

Timescales are set by the specific subcontract, not by general practice. Standard form subcontracts commonly require submission within a set number of weeks or months after practical completion of the subcontract works, with a further period for the contractor to respond - check the relevant clause rather than assuming a default deadline.

What documents do I need to agree a subcontractor final account?

As a minimum: the priced subcontract sum analysis, a variation and instruction log, daywork sheets, any loss and expense claim with supporting records, the payment and application history, and evidence for any contra charges or deductions. See the checklist table above for a fuller breakdown.

Can a main contractor withhold subcontractor retention indefinitely?

No. Retention should be released according to the terms of the subcontract, typically in two tranches at practical completion and at the end of the defects liability period. Withholding it beyond that without a valid contractual reason is a common source of disputes and can be challenged through adjudication.

What happens if the contractor and subcontractor can't agree the final account?

Most subcontracts preserve the right to adjudication if a final account dispute can't be resolved through negotiation. It is important to raise any disagreement within the contractual time limit for doing so, since missing that window can leave a party time-barred from challenging the assessment later.

Does the subcontract final account have to wait for the main contract final account?

Not entirely. Subcontractors are entitled to payment within their own subcontract's timeframes regardless of the main contract's progress, but main contractors often prefer to have clarity on their own account with the client before finally signing off subcontract items that depend on the same underlying issue, such as an extension of time.

What's the difference between a subcontractor final account and a main contract final account?

A subcontractor final account covers only that subcontractor's package and sits between the subcontractor and the main contractor. The main contract final account covers the whole project and sits between the main contractor and the client. They are separate documents, though entitlements often flow from one into the other.

Final Thoughts

Agreeing a subcontractor final account well isn't complicated in principle - it's a reconciliation exercise - but it takes discipline to execute cleanly. The accounts that close quickly are the ones where variations were priced and agreed as they arose, claims were supported with contemporaneous records rather than reconstructed after the fact, and retention was tracked properly from day one.

Where accounts drag on, it's almost always because one of those three things was missing, and both parties are now trying to reconstruct a paper trail from memory. Build the discipline into how you run the subcontract from the start, and the final account becomes a formality rather than a fight.