A method, comprising: by a user equipment, UE: initiating an application on the UE, while connected with a first cellular network, wherein the first cellular network does not support network slicing; determining slice related information for the application; determining if a UE route selection policy, URSP, contains a non-default rule for a packet data protocol, PDP, context between the UE and the first cellular network, wherein: when the URSP contains a non-default rule for the PDP context between the UE and the first cellular network, the method further comprises determining, according to the non-default rule of the URSP, a proposed single network slice selection assistance information, S-NSSAI, wherein the slice related information is the proposed S-NSSAI; when the URSP does not contain a non-default rule for the PDP context between the UE and the first cellular network, and when the PDP context is associated with a service related to a slice provided by a specific network slice customer, NSC, the method further comprises determining an identifier of the NSC, wherein the slice related information is the identifier of the NSC; providing the slice related information to the first cellular network; and receiving a S-NSSAI from the first cellular network, wherein the S-NSSAI was determined based at least in part on the slice related information provided by the UE to the first cellular network; wherein the S-NSSAI is useable when the UE transitions to a second cellular network that does support network slicing. initiating an application on the UE, while connected with a first cellular network, wherein the first cellular network does not support network slicing; determining slice related information for the application; determining if a UE route selection policy, URSP, contains a non-default rule for a packet data protocol, PDP, context between the UE and the first cellular network, wherein: when the URSP contains a non-default rule for the PDP context between the UE and the first cellular network, the method further comprises determining, according to the non-default rule of the URSP, a proposed single network slice selection assistance information, S-NSSAI, wherein the slice related information is the proposed S-NSSAI; when the URSP does not contain a non-default rule for the PDP context between the UE and the first cellular network, and when the PDP context is associated with a service related to a slice provided by a specific network slice customer, NSC, the method further comprises determining an identifier of the NSC, wherein the slice related information is the identifier of the NSC; providing the slice related information to the first cellular network; and receiving a S-NSSAI from the first cellular network, wherein the S-NSSAI was determined based at least in part on the slice related information provided by the UE to the first cellular network; wherein the S-NSSAI is useable when the UE transitions to a second cellular network that does support network slicing. determining slice related information for the application; determining if a UE route selection policy, URSP, contains a non-default rule for a packet data protocol, PDP, context between the UE and the first cellular network, wherein: when the URSP contains a non-default rule for the PDP context between the UE and the first cellular network, the method further comprises determining, according to the non-default rule of the URSP, a proposed single network slice selection assistance information, S-NSSAI, wherein the slice related information is the proposed S-NSSAI; when the URSP does not contain a non-default rule for the PDP context between the UE and the first cellular network, and when the PDP context is associated with a service related to a slice provided by a specific network slice customer, NSC, the method further comprises determining an identifier of the NSC, wherein the slice related information is the identifier of the NSC; when the URSP contains a non-default rule for the PDP context between the UE and the first cellular network, the method further comprises determining, according to the non-default rule of the URSP, a proposed single network slice selection assistance information, S-NSSAI, wherein the slice related information is the proposed S-NSSAI; when the URSP does not contain a non-default rule for the PDP context between the UE and the first cellular network, and when the PDP context is associated with a service related to a slice provided by a specific network slice customer, NSC, the method further comprises determining an identifier of the NSC, wherein the slice related information is the identifier of the NSC; providing the slice related information to the first cellular network; and receiving a S-NSSAI from the first cellular network, wherein the S-NSSAI was determined based at least in part on the slice related information provided by the UE to the first cellular network; wherein the S-NSSAI is useable when the UE transitions to a second cellular network that does support network slicing.