Recording and billing variation work without disputes

It happens on the scaffolding, in the meter cupboard or over coffee: could you 'just quickly' add that extra circuit? You say yes, because you are there anyway. Three weeks later someone in the office writes the final invoice and the extra work is not on it. Or it is on it, and the client says nobody ever told them a price. Recording variation work is not an administrative afterthought that will sort itself out later. It is the condition for being allowed to bill it at all. In this article: what Dutch law demands, what unbilled extra work costs you per year, what you can fix for free, and which part you can automate at the moment it happens.

Unbilled extra work does not cost you revenue, it costs you profit

When you lose a quote, you lose revenue you never had. Extra work you fail to bill is different: the hours were worked, the wages were paid, the material was used. Whatever you do not charge for comes straight off your profit. A lost quote costs you an opportunity. Unbilled extra work costs you money you have already spent.

It rarely disappears in one way. Usually in five at once:

• It was agreed verbally on site and never entered anywhere. Nobody in the office knows it exists.
• It is on the job sheet, but without a price and without approval, so nobody dares put it on the invoice.
• It gets absorbed into the project budget because it was 'only an hour', a classic that construction software suppliers themselves name as the main cause of lost revenue (source: ECI Solutions).
• The client queries it, it turns awkward, and to keep the relationship sweet you let it go.
• It is neatly on a list, but the final invoice has already gone out.

The law: no timely warning, no price increase

The main rule is in article 7:755 of the Dutch Civil Code and it is shorter than most people think. For additions or changes to the agreed work requested by the client, the contractor may only claim a price increase if they warned the client in time about the necessity of the resulting price increase, unless the client should have understood that necessity by themselves.

Read that word 'in time' again. In time means: before you carry it out. A variation line that first appears on the final invoice is not in time, however justified it is. And note what it does not say: it does not say you must quote an exact amount up front. You must point out the necessity of a price increase.

The Dutch Supreme Court confirmed this on 1 July 2022 (ECLI:NL:HR:2022:989). For the exception at the end of the article, the client should have understood it themselves, it is not required that they also had insight into the size of the increase or the concrete extra costs to be expected. They had to understand that it would get more expensive. That is friendlier to you than most advice pieces suggest. But it is no blank cheque: in the same ruling the court holds that where the amount of the increase was not agreed, article 7:752 applies. You are then owed a reasonable price, and a guide price may be exceeded by no more than 10 percent unless you warned as early as possible that it would go beyond that.

If you work for private individuals, a second layer applies. Consumers are covered by separate information duties about price (articles 6:230l and 6:230m of the Civil Code), which bite hardest for contracts you sign away from your own premises, at the client's kitchen table, in other words. Trade body Bouwend Nederland writes that failing to meet an information duty quickly means 'a discount of 25% to 50% on the extra price'. If you work for a main contractor or another business client, those consumer rules do not apply, but article 7:755 still does.

Two problems that look alike and need different fixes

• Problem 1: no timely warning. The work is done and the client did not know it cost extra. You have legally lost the right to that price increase, however good your admin is.
• Problem 2: you did warn, the client agreed, but nothing was recorded or it was left sitting. You have the right, just not the invoice line.

Almost every company that tackles this goes after problem 2. That is the visible one: job sheets, lists, software. Problem 1 quietly keeps running, and that is the expensive one, because that is where the big amounts sit, the unforeseen work that turns into an argument afterwards. The fix for problem 1 is not administrative. It lives in the five minutes after the client says yes.

Fix this first, no AI needed

• Put in your quote not only what is included, but what is not. If your scope is open, every conversation about extra work automatically becomes an argument about what was already paid for.
• Give your field staff one fixed sentence. 'That can be done, but it is extra work and it goes on the bill, I will send you a message to confirm.' That is all the warning duty requires.
• A message from the client saying 'yes, go ahead' is usable evidence and costs nothing. A verbal agreement on a roof is not.
• Agree who decides when it is borderline. If the fitter is not allowed to judge it and you do not pick up, they will just do it and say nothing.

If this is not in place, automation will not save you. You will only make the mess faster. This costs you one evening and a rewritten quote template, and it is the first thing I would do.

What automation does add: the moment itself

The gap sits between 'the client says yes on site' and 'the office knows about it'. At most companies that gap is hours to weeks, and the money disappears in exactly that gap. Nobody fills in a form on a roof at quarter to four, and that is not a discipline problem. So you remove the threshold instead of holding another meeting about it. Concretely, well-built automation can:

• Record it in twenty seconds. The fitter speaks what they found or takes a photo, and out comes a tidy variation line: what, why, estimated hours, material, which job and which client.
• Send the client a confirmation straight away in your own standard wording, with the price indication included. That is exactly the warning the law asks for, at the moment it is still valid: before the work.
• Record the client's approval against the job, with date and time. A 'yes, fine' by message or email is enough, as long as it is kept with the project and not in someone's phone.
• Put the line on that project's invoice list as soon as approval comes in, so invoicing becomes a check instead of a search.
• Watch what gets stuck. Extra work sitting three days without approval is a signal. A project being closed while approved, unbilled extra work is still open should not get through.
• Show you every quarter which type of job structurally generates extra work. If it is the same situation three times over, it does not belong in your variations, it belongs in your quote.

That last point pays off most over time and almost never gets built. Extra work that comes back every time is not extra work, it is a costing error you have been repeating for three years.

What this does not solve

• A client who simply refuses to pay. That argument stays, except now you have it with a timestamp and an approval instead of your memory.
• Large clients with their own variation procedure: reference numbers, a portal, or terms from the standard construction conditions. Then your automation follows their form, not the other way round. Perfectly doable, but it is their process and it gains you less.
• Sending prices to clients automatically with nobody looking. That is exactly the kind of message where one mistake costs you a client or a margin. Route it past a human for the first stretch and only then build out the exceptions.
• A company with two variation sheets a month. Buy nothing. Rewrite your quote template and you are done.

What it costs and where you start

First check whether off-the-shelf software already does it. There are job sheet and project apps for Dutch construction and installation firms costing a few tens of euros per employee per month that handle the recording perfectly well. If that solves your problem, buy that. I do not rebuild what you can buy ready-made; custom-building something that exists for a tenner never pays for itself.

If the gap remains, the moment on site, the confirmation to the client, the watch on what never got billed, then for most companies this is a small to medium project: somewhere between 300 and 5,000 euros for the recording and confirming, and 5,000 to 12,000 euros if it has to hang tightly off your project administration and invoicing. Maintenance after that from 100 euros a month, cancellable monthly. Put that next to the figure you calculated for yourself above.

• 1. Getting acquainted: Where does your time go, and which systems do you use? We discuss how your business works.
• 2. Opportunities & proposal: You receive a proposal covering automation opportunities, connections, timing and costs.
• 3. Building & testing: I build your system step by step and keep you updated. We test, improve and expand it.
• 4. Live & beyond: Once everything runs well, we launch the system. You track your AIs and their actions in your own dashboard.