early 15c., "gather into one place or group" (transitive), from Old French collecter "to collect" (late 14c.), from Latin collectus, past participle of colligere "gather together," from assimilated form of com "together" (see com-) + legere "to gather," from PIE root *leg- (1) "to collect, gather."
The intransitive sense "gather together, accumulate" is attested from 1794. Related: Collected; collecting. As an adjective or adverb meaning "paid by the recipient," it is attested from 1893, originally with reference to telegrams.