It is the 5th of the month. On your desk lies an invoice with the line ‘additional work week 34, €3,200’. No work order, no supporting evidence, no reference to who approved it. You vaguely recall a phone call in August, but you cannot find it. The payment term keeps ticking. And once again you lose half an afternoon on detective work that yields nothing but frustration, both for you and for the supplier.
The discussion about invoicing additional work in a contract feels like a financial problem. It is not. It is a contract management problem that only becomes visible the moment the invoice arrives. The solution does not lie in stricter invoice checks, but in agreements and performance data recorded months earlier.
The discussion starts not with the invoice, but months earlier
An invoice for additional work is a symptom. By the time you hold it in your hands, it is too late to clarify what was actually agreed. The information you need to judge whether that €3,200 is justified should already have been there: what falls within the contract scope, who was allowed to approve additional work and up to what amount, and what was actually delivered.
Without that foundation, the same back-and-forth plays out every month. The supplier says it was additional work. You are not sure. The person who gave approval has left or is on holiday. Often you simply keep paying to avoid the hassle. That is exactly where the savings leak away, the ones you negotiated so sharply during the tender.
Regular scope or additional work: where exactly is the difference?
Take a cleaning contract for an organisation with 12 locations. The periodic cleaning, daily and weekly according to a fixed programme, falls within the regular scope. It is included in the contract rate. The supplier simply invoices it monthly, without discussion.
Additional work is everything outside that. An emergency clean-up after a leak. An extra cleaning round after an event. Floor maintenance that was not in the annual programme. That may be charged separately, provided it was approved in advance and supported afterwards by a work order or timesheet.
The distinction becomes tricky with an all-in rate or fixed price. There, additional work is not included in the price, so every deviation is a potential discussion. Anyone without a clear scope definition on record cannot objectively determine which side of the line a task falls on. And then it is not the one who is right who wins, but the one with the most stamina.
The three places where you lose your agreements
Agreements about invoicing additional work almost always disappear in the same three places. And at the moment of invoicing, no one has them to hand.
- The contract itself. The scope definition sits somewhere in a 40-page appendix that no one opens any more. The agreement about additional work is there, but not linked to a place where you actually use it.
- The email exchange. Changes and one-off approvals go by email. Three months later you are searching through hundreds of messages for that single ‘go ahead’ the supplier treats as approval.
- The loose work orders. Paper or scanned orders lying around somewhere per location. No one keeps them systematically, so the supporting evidence only surfaces when you ask for it. If it exists at all.
As long as these three sources live separately in Excel files and mailboxes, every invoice review remains a reconstruction after the fact. That is not control, that is archaeology.
What to record in advance to avoid the discussion
You do not prevent the discussion about invoicing additional work with stricter invoice checks, but with four agreements you record in one place at the start of the contract.
- Scope definition. What falls under the regular rate and what explicitly does not. Concrete enough that a new colleague can still read and apply it six months later.
- Approval authority. Who may approve additional work on behalf of the organisation. Not ‘someone from FM’, but a name and a role.
- Threshold amounts. Up to what amount someone may approve independently, and from what amount a second signature is required.
- Method of recording. How approval is registered. A verbal ‘yes’ does not count, a recorded approval with date and amount does.
Record this in a place both the client and the supplier can access, and the discussion shifts from the moment of invoicing to the moment of the contract. Exactly where it belongs.
Performance data makes the invoice review objective
Recording agreements is half the job. The other half is knowing what was actually delivered. When the delivered performance is linked to the contract agreement, the invoice review becomes objective. You are not comparing two opinions, but the invoice against the data.
Back to the emergency clean-up. Is there an approved additional-work order from August with an amount and a signature, linked to a work order confirming the execution? Then the invoice is signed off in five minutes. If either is missing, you have a concrete starting point for the conversation. In both cases the discussion is settled on facts, not on who shouts the loudest.
This link between contract agreement, performance measurement and invoice is the difference between reactive disputing and controlled sign-off. The monthly invoicing moment then becomes a moment of control, not of conflict. Organisations that adopt this way of working save time on administration. They also keep a grip on the tender savings that would otherwise slip away through uncontrolled additional work. GRIP aims for an average of 8% cost savings per year and 30% less time spent on contract administration, provided the agreements and data really do sit in one place.
One shared truth for client and supplier
The heart of the invoice discussion is that the client, the supplier and sometimes an adviser each look at their own version of the truth. Each has their own Excel, their own mailbox, their own orders. As long as that is the case, every deviation remains a negotiation.
GRIP brings scope, agreements and performance together in one place where both parties look at the same data. In financial management you link additional work to an approved agreement and the accompanying supporting evidence. Through contract management you see how delivered performance relates to what was agreed. Anyone still working with loose files will probably recognise the pattern from why Excel falls short for contract management.
Want to move the additional-work discussion from the moment of invoicing to the moment of the contract? Book a demo and see how scope, agreements and performance come together in one dashboard.