By a majority of eight to one (524 to 60), JCSA members voted in favour of merging with Prospect in an all-members’ ballot.
The 855-strong association will become a branch of Prospect once detailed arrangements are finalised, said JCSA President John Moulin.
“This is an important decision for everyone who works for the island government. I am delighted members have supported the JCSA committee’s recommendation by such a large margin.
“It is a brave decision given that the Jersey Civil Service Association has been in existence since approximately 1949, but I and my committee believe it is the right one in today’s busy and challenging climate.
"It will enable us to improve and expand our range of services to members, whilst at the same time preserving our local autonomy and identity, which members rightly value highly.”
Prospect Deputy General Secretary Mike Clancy said: “We are delighted by the result and look forward to working on behalf of members in the JCSA. We aim to build on the record of the Association by using our experience and negotiating capacity.”
The JCSA will join with comparable organisations, the Association of Guernsey Civil Servants, which merged with Prospect at the start of 2008, and the Isle of Man Government Officers Association, which has been part of Prospect since 1990.