On March 1, 1967, the Post Office Component, whose origin goes back to the convention meeting of the Railway Mail Clerks in Ottawa in November 1966, joined the Public Service Alliance of Canada. This joining made the component and the PSAC the successors to the Canadian Railway Mail Clerks Federation, which was founded  in 1889, and as such, is the oldest union at Canada Post.

At the Postal Communications Component Convention in Halifax in August 1975, the elected delegates voted unanimously to change the name of their component to the Union of Postal Communications Employees (UPCE).

UPCE has members in 2 different bargaining units. The largest of these is the Canada Post group, today numbering about 1,800 members. UPCE members at Canada Post are employed mainly in an administrative, clerical, technical, and/or professional capacity.

The other bargaining unit is situated in British Columbia, and these approximately 140 members are employed by Purolator Courier Ltd. The Purolator bargaining unit members perform clerical and administrative duties. They are also retail representatives in the Purolator retail stores in B.C.

The UPCE, as do the other Components of the PSAC, holds a National Convention every three years at which time elected delegates from all the Locals establish the budget and policy of the Union and elect the National Executive.