A collective agreement is valid from the day it is signed unless otherwise agreed by the parties, unless it is rejected by a majority vote in a confidential ballot held within four weeks of the date of signature. For a valid vote, at least one fifth of those on the voting roll or membership register, working under the agreement must participate.
Trade unions belonging to the same national federation, which has signed on their behalf a general collective agreement, can decide to put that agreement under a joint ballot for members of all the participating trade unions. If a general confidential postal ballot is held, its result is valid irrespective of participation rate. If two or more trade unions are involved in a collective agreement for members at the same place of work (enterprise agreement), it must be put jointly to a ballot involving all the members to whom it applies.