Final Accounts for Trade Businesses UK 2026 — Closing Out a Job & Getting Paid

What a Final Account Actually Is

A final account is the agreed final figure for a job once the original contract sum has been adjusted for everything that changed during the works. You start from what you priced, then you add and subtract every documented adjustment until you reach a single number that both you and the client accept as the full and final value of the work.

On a typical job, the things that move the number between quote and final figure are:

• Variations: changes the client asked for, or that became necessary, that were not in the original scope — extra sockets, a different worktop, an additional wall taken down.
• Provisional sums: allowances put into the original price for work that could not be fully measured or specified at quote stage. These are replaced with the actual cost once the work is known.
• Prime cost (PC) sums: an allowance for a specific item the client will choose later — for example "£600 PC for sanitaryware." The allowance is adjusted up or down to the actual chosen item.
• Dayworks: work done on a time-and-materials basis where it could not sensibly be priced as a fixed item — usually recorded on signed daywork sheets.
• Deductions: contra charges, omitted work, or amounts held back for incomplete or defective work.
• Retention: a percentage held back by the client until any defects are made good, released later.

Why Getting the Final Account Right Matters

The final account is where your profit on a job is either confirmed or quietly eroded. Most trades are diligent about pricing the original quote and then casual about everything that follows — and that is exactly where margin leaks. A few extras done as favours, a provisional sum left at the original allowance even though the real cost was higher, a daywork day never written down: each of these is real money that never makes it onto the invoice.

A clear final account also protects your cash flow. The longer the gap between finishing the work and agreeing the final figure, the colder the trail goes and the harder the conversation becomes. A customer who has just watched you complete the job is far more receptive to a tidy, itemised account than one who receives a surprise bill three months later.

Finally, it is your main defence against disputes. When every line is backed by a documented variation or a signed daywork sheet, there is very little for the client to argue with. When the number arrives with no breakdown, every pound becomes negotiable and you spend more time chasing than working.

How to Prepare a Final Account, Step by Step

1. Start from the original contract sum

Begin with the figure the customer agreed at the outset — the quoted price or contract sum. This is your baseline. Pull out the original quote and use the exact figure that was accepted, not a rounded or remembered version.

2. Add agreed variations

Go through every variation raised during the job. For each one, you want a description, a price and ideally a sign-off — an email, a text, a signed variation slip, anything that shows the client agreed. Add the total value of all agreed variations to the contract sum. This is the single most common place trades undercharge, because small extras get done in the moment and never get written up.

3. Adjust provisional and PC sums to actual

For every provisional sum and prime cost sum in the original price, remove the allowance and substitute the actual cost. If you allowed £600 for tiling as a provisional sum and the real cost came to £820, you deduct the £600 allowance and add the £820 actual. If the client chose a cheaper item than a PC allowance, the number comes down — and showing that honestly builds trust for the lines where it goes up.

4. Add dayworks

Add the value of any work carried out on a daywork basis, supported by your daywork sheets. Each sheet should show the date, the hours, the labour rate, materials used and plant or hire charges — and ideally a signature from the client or their representative confirming the time was spent. Unsigned dayworks are far weaker to defend, so get them signed as you go.

5. Deduct for incomplete or defective work and contra charges

Be honest about anything not finished or not right. If a section was left incomplete, or there is defective work still to put right, either deduct a fair value or note it as a hold-back to be released once made good. Include any agreed contra charges — for example, where the client supplied materials you were due to provide, or where you used another trade's facilities by arrangement. Showing these deductions yourself, before the client raises them, makes the whole account more credible.

6. Account for retention, if applicable

If the contract includes retention — commonly around 5%, sometimes 3% — show the gross final figure, then the retention held, then the amount due now. Make clear when the held amount becomes due: usually a portion at practical completion and the balance at the end of the defects period. Retention is covered in more detail below.

Worked Example: Building Up a Final Account

Here is a simplified build-up for a domestic bathroom and bedroom refurbishment, to show how the original contract sum moves to a final figure. Your own jobs will differ, but the structure is the same.

Figures are illustrative only. Always work from your own quote, signed variations and daywork records, and apply the retention terms in your actual contract.

The Real Secret: Document Variations as You Go

A clean final account is not something you assemble at the end — it is something you build throughout the job. The trades that close out smoothly are the ones who write up every variation when it happens, get a quick sign-off, and keep daywork sheets signed. The ones who struggle are those trying to reconstruct three months of changes from memory once the customer has the keys and the goodwill has cooled.

Make it a habit. The moment a client asks for something outside the original scope, confirm it in writing: a short message saying "happy to do that — it'll be an extra £X, let me know to proceed" is enough. Their reply is your sign-off. Keep the original quote, every variation, every PC and provisional adjustment, and every daywork sheet together in one place per job. When the work finishes, the final account practically writes itself, and every line has evidence behind it.

This is exactly the kind of record-keeping that is easy to let slip when you are busy on the tools — and exactly where job management software earns its keep, by capturing variations and notes against the job as they happen rather than relying on memory and scraps of paper.

Presenting the Final Account Clearly

How you present the account matters almost as much as the figures in it. A single total with no breakdown invites suspicion; a clear itemised statement invites agreement. Lay it out so the client can follow the logic from the original price to the final figure.

• Start with the original contract sum so the client recognises the starting point.
• List each variation with a short description and its value — group additions and omissions clearly.
• Show provisional and PC adjustments as "allowed £X, actual £Y" so the change is transparent.
• Reference the daywork sheets by date and attach copies.
• Show any deductions or contra charges plainly — do not bury them.
• Finish with the gross final figure, retention if any, payments already made, and the balance due.

Send it promptly while the job is fresh, and offer to talk it through. A two-minute walk-through of the account on site or over the phone heads off most queries before they become disputes.

Handling Negotiation and Retention Release

On larger or commercial jobs, the client may come back with queries or want to negotiate certain lines. This is normal. The stronger your documentation, the smaller the negotiation — lines backed by a signed variation or daywork sheet are hard to argue down, while "trust me" lines are where you will be squeezed. Decide in advance which items you can flex on and which you cannot, and keep the tone collaborative rather than combative.

Where retention applies, be clear about the release mechanism. Typically a portion is released at practical completion (when the work is usably finished) and the remainder at the end of the defects liability period (often six or twelve months) once any snags raised have been put right. Diarise the retention release date so the final tranche does not get forgotten — unclaimed retention is one of the most common forms of money quietly left behind in the trades. When the defects period ends, send a short note requesting release of the balance, referencing the agreed final account.

For smaller domestic jobs without formal retention, the equivalent risk is the customer holding back the last payment over minor snags. Address this by snagging proactively — walk the job with the client, list anything outstanding, fix it, and then issue the final account against a job everyone agrees is complete.

Frequently Asked Questions

Is a final account the same as a final invoice?

Not quite. The final account is the agreed statement of the total value of the work, showing how you got from the contract sum to the final figure. The final invoice is the request for payment that follows once the account is agreed. On smaller jobs the two are often combined into one document, but on larger jobs the account is agreed first and invoiced afterwards.

What is the difference between a provisional sum and a PC sum?

A provisional sum is an allowance for work that could not be fully measured or specified when the job was priced — it is adjusted to the actual cost once the work is known. A prime cost (PC) sum is an allowance for a specific item the client will choose later, such as a particular tap or tile, adjusted up or down to the cost of whatever they pick.

What if the client never signed off the variations?

Unsigned variations are harder to claim but not automatically lost — any written evidence (texts, emails, photos, your job notes) helps. The lesson for next time is to confirm every variation in writing and get a quick acknowledgement before doing the work. Going forward, build the habit so this never costs you.

How much retention is normal?

On UK construction work retention is commonly 3% to 5%, typically split so half is released at practical completion and half at the end of the defects period. The exact figure and timing should be set out in your contract before work starts — never assume a percentage.

When should I send the final account?

As soon as the work is practically complete and any snags are agreed. Sending it promptly, while the job is fresh in the client's mind, gives you the best chance of quick agreement and payment.

A Note on Scope

This article is general guidance to help trade businesses prepare and present a final account. It is not legal or contractual advice. The terms of your own contract — including how variations, provisional and PC sums, dayworks, retention and payment are dealt with — take precedence. For significant disputes, or where large sums are at stake, seek advice from a quantity surveyor or a solicitor experienced in construction contracts.