A plug-in coupling for fluidic systems, in particular for CO2- and fuel-conducting systems, including a housing (1) and a plug (2) which can be inserted into the housing (1). The plug (2) can be inserted by a plug stem (3) into a receiving opening (4) of the housing (1) in a manner sealed by at least one circumferential seal (5, 5a, 5b) and, when inserted, for it to be locked therein against release by a locking device having at least one latching element (7) arranged on the plug (2) and a latching shoulder (8) interacting with the latching element (7). The housing (1) has two-part design with an inner housing part (1a) and an outer housing part (1b), which can be connected releasably to the inner housing part (1a) so that it essentially surrounds the inner housing part (1a). In order to install it without destroying it, the latching shoulder (8) is formed at one end in an entry region (4a) of the receiving opening (4) on the outer housing part (1b).