The trainer's signature at the bottom of the sheet does not prove that the trainer was there.
It proves that someone signed in that spot. That is not the same thing, and the difference is paid for at the moment you are asked to show that a session actually took place.
What a check actually asks for
Whoever pays for a course, or inspects it, does not want a signature. A funder, a corporate client, an accreditation body or an inspector wants documents that establish that the course was delivered, and a course is not delivered by a room and some chairs. It is delivered by someone, teaching defined content. That someone must therefore be linkable to the session, and a signature on its own is not enough, because it says neither who, nor on what, nor in what capacity.
The consequence is easy to underestimate. When the documents fail to establish delivery, the doubt does not stay politely confined to the trainer's line on the sheet. It spreads to the course, because the course is what was paid for.
What actually links a trainer to a session
The training agreement usually provides for it already. A well-drafted agreement states the means committed to the course, and the trainer is one of them, the main one. If the trainer is named there, their presence fits into a commitment made before the start, which is precisely what a signature on the day cannot produce.
Three documents answer one another. The agreement says who was to teach. The programme says on what. The payment (a payslip for an employee, an invoice for an outside trainer) says in what capacity, and it carries a date that nobody created for the audit. The signature confirms that someone was there. It is useful; it is not primary.
This is why a forgotten trainer signature can be repaired, while a missing link cannot. In the first case, three documents still agree with one another. In the second, there is nothing left to bring into agreement.
The case that brings files down
It is not a rare case: one trainer stands in for another at short notice.
The agreement names Mark; Sophie came instead. Sophie signed the sheet, and everything looks in order. Two years later, the auditor reads an agreement in Mark's name, a sheet signed by Sophie, and an invoice from Sophie for a course she was not engaged to teach. Nothing is false, everything is inconsistent, and it is the inconsistency that gets sanctioned, not fraud.
The remedy fits in one line: an amendment, or even a simple dated note added to the file, recording the replacement. Written on the day, it is evidence; reconstructed afterwards, it is only an explanation.
An order of magnitude, and what it really costs
Take a three-day course for twelve people, invoiced at a few thousand euros. Three days make six half-days. A half-day whose trainer cannot be documented is one sixth of the teaching time. It is tempting to think that the risk is in proportion: a sixth of the invoice at worst.
It is not. The question a funder or a client asks is not "how many half-days are documented?" but "did this course take place, as agreed?". A course whose trainer cannot be identified for part of it is a course whose delivery is in doubt as a whole, and the amount at stake is the invoice, not a sixth of it.
What to take away
The question "did the trainer sign?" is the wrong one. The right one is: if I take the sheet out of the file, is there still enough to establish who taught this session, on what content, and under what commitment?
A centre that answers yes has evidence. A centre that answers no has a signature.
Sources
This article cites no legal text. Its argument rests on what each document in a training file can and cannot establish, and on arithmetic set out in the body.