Attachment system for mounting a dispensing pump on a vial and associated vial of fluid product

The invention relates to a system for attaching a dispensing pump on the neck of a reservoir containing a fluid product. The system a sleeve with attachment means on the neck and hooking means of the pump, an articulation collar, the articulation collar and sleeve being mounted mobile with respect to one another between an end of motion position (PF) and a start of motion position (PI), a shrink ring configured to move along the articulation collar between a top disassembly position (PH), wherein the attachment means are free, and a bottom position (PB) of use, wherein the attachment means are engaged around the neck and wherein the start and end of motion positions (PI, PF) are arranged so that the articulation collar can go from the top disassembly position (PH) to the bottom position (PB) of use by a translational motion.