Fitting for a pipe, in particular a plastic pipe or a plastic-metal composite pipe, having - a main body having a passage for a fluid; - a connecting body which is releasably connectable to the main body and likewise has a passage for a fluid which is connectable to a pipe; - wherein both bodies (12, 16) have contact faces (26, 28) which are insertable into one another and which have at least one pair of mutually opposite depressions (30, 32) which form a receptacle space; and - a substantially uncompressible and flexible locking element for securing the two bodies (12, 16) to one another, which is introducible into the receptacle space; characterized in that - at least one of the two bodies (12, 16) has a first and a further access space (36, 38), wherein the first access space (36, 38) adjoins the receptacle space so as to substantially extend the latter, and wherein the first and the further access space (36, 38) at mutually opposite ends of the receptacle space in each case preferably continuously and without protrusions open thereinto and in a mutually adjacent manner terminate on an external face of the main body and/or of the connecting body, wherein the external face comprises protrusions having mutually adjacent faces which run at an angle in relation to one another; - wherein the locking element, for preventing the locking element unintentionally slipping out of the receptacle space, on one of its mutually opposite ends has a latching protrusion for externally latching the locking element on at least one of the two bodies (12, 16) between the mutually adjacent faces which run at an angle in relation to one another. - a main body having a passage for a fluid; - a connecting body which is releasably connectable to the main body and likewise has a passage for a fluid which is connectable to a pipe; - wherein both bodies (12, 16) have contact faces (26, 28) which are insertable into one another and which have at least one pair of mutually opposite depressions (30, 32) which form a receptacle space; and - a substantially uncompressible and flexible locking element for securing the two bodies (12, 16) to one another, which is introducible into the receptacle space; characterized in that - at least one of the two bodies (12, 16) has a first and a further access space (36, 38), wherein the first access space (36, 38) adjoins the receptacle space so as to substantially extend the latter, and wherein the first and the further access space (36, 38) at mutually opposite ends of the receptacle space in each case preferably continuously and without protrusions open thereinto and in a mutually adjacent manner terminate on an external face of the main body and/or of the connecting body, wherein the external face comprises protrusions having mutually adjacent faces which run at an angle in relation to one another; - wherein the locking element, for preventing the locking element unintentionally slipping out of the receptacle space, on one of its mutually opposite ends has a latching protrusion for externally latching the locking element on at least one of the two bodies (12, 16) between the mutually adjacent faces which run at an angle in relation to one another.