The principle: any contract modification must be formalized in a written amendment
The collective agreement sets a clear rule in its common framework: the employment contract is concluded in writing, and any subsequent modification must be formalized in a written amendment. Verbal agreements, text messages, or simple emails are not sufficient to validly modify the terms of a contract.
In practice, a written amendment is required whenever a key element of the contract changes:
- change in working hours or weekly schedule,
- new usual work location,
- addition or modification of tasks assigned to the employee,
- any salary adjustment linked to a change in working conditions.
Like the initial contract, the amendment must be drawn up in two copies, dated, signed, and initialed by both parties, each keeping one copy.
The exception: voluntary salary increase without changes to working conditions
There is a useful nuance, often overlooked: a voluntary salary increase that does not involve any change to working conditions (same hours, same location, same tasks) does not necessarily require a formal amendment. This is an important distinction from the common misconception that any contract change, including a simple salary adjustment, automatically requires an amendment.
However, as soon as another contract element changes alongside the salary adjustment, or the change concerns something other than an increase in pay, the written amendment becomes the rule again.
Why this formalism matters in practice
The absence of a written amendment does not make the employment relationship illegal, but it deprives both parties of a document that can be used as evidence in case of disagreement. This is particularly critical in situations involving:
- hours worked, when the employee disputes (or claims) a change in schedule that was never formalized;
- an employee’s refusal to perform a task or work at a new location not specified in the initial contract, a refusal that cannot then be held against them;
- informal changes that one party may have considered temporary while the other saw them as permanent.
A dated and signed amendment clearly establishes, at a given moment, what was agreed upon between the household and the employee.
What Kiwisio offers in practice
- An amendment workflow linked to the original contract, with clear traceability of the history of modifications (hours, location, tasks) rather than scattered exchanges via text or email.
- The assistant, integrated into Kiwisio, to check whether a given modification requires a written amendment before implementing it.
- Digital signature of the amendment, just like the initial contract, allowing the household and the employee to sign directly via Kiwisio without having to organize paper exchanges.
The goal is not to multiply unnecessary formalities, but to secure the changes that truly matter, without leaving the employment relationship dependent on oral agreements that are difficult to prove.