Method for providing IP services to a user of a public network, wherein - the user accesses the public network using a user equipment, - the user equipment supports a first set of IP services, - the network provides a second set of IP services, comprising the steps of - identifying a third set of IP services comprised in said first and second set of IP services, - allowing said user to access a plurality of IP services of said third set, wherein said plurality of IP services are a plurality of IMS services, and wherein: a first authentication system of said network collects information relating to the user equipment when the user accesses the network, a provisioning system of said network provisions network registers with user related data, a service locator function server (SLF*) of said network stores data relating to users allowed to access IMS services provided by the network and data relating to a user equipment associated to said user, wherein said network registers are associated to said plurality of IMS services, and wherein said service locator function server (SLF*) compares the information relatin to the user equipment collected by said first authentication system with said data relating to user equipment -stored by said service locator function server (SLF*), so as to request said provisioning system to provision said registers if information relating to the user equipment collected by said first authentication system was not stored by said service locator function server SLF*. - the user accesses the public network using a user equipment, - the user equipment supports a first set of IP services, - the network provides a second set of IP services, comprising the steps of - identifying a third set of IP services comprised in said first and second set of IP services, - allowing said user to access a plurality of IP services of said third set, wherein said plurality of IP services are a plurality of IMS services, and wherein: a first authentication system of said network collects information relating to the user equipment when the user accesses the network, a provisioning system of said network provisions network registers with user related data, a service locator function server (SLF*) of said network stores data relating to users allowed to access IMS services provided by the network and data relating to a user equipment associated to said user, wherein said network registers are associated to said plurality of IMS services, and wherein said service locator function server (SLF*) compares the information relatin to the user equipment collected by said first authentication system with said data relating to user equipment -stored by said service locator function server (SLF*), so as to request said provisioning system to provision said registers if information relating to the user equipment collected by said first authentication system was not stored by said service locator function server SLF*. a first authentication system of said network collects information relating to the user equipment when the user accesses the network, a provisioning system of said network provisions network registers with user related data, a service locator function server (SLF*) of said network stores data relating to users allowed to access IMS services provided by the network and data relating to a user equipment associated to said user, wherein said network registers are associated to said plurality of IMS services, and wherein said service locator function server (SLF*) compares the information relatin to the user equipment collected by said first authentication system with said data relating to user equipment -stored by said service locator function server (SLF*), so as to request said provisioning system to provision said registers if information relating to the user equipment collected by said first authentication system was not stored by said service locator function server SLF*.