A method for use in a communications network, the method carried out by a mobile device or a User Equipment or carried out by a Mobile Switching Center, MSC, the method comprising the step of: creating an Instance Identifier, ID, to uniquely identify the mobile device or the User Equipment, UE, in the communications network whilst ensuring the privacy of existing mobile device or UE identities, wherein the creation of the Instance Identifier is based on: selecting a hash algorithm from one of MD5 or SHA-1; creating a Unique identifier that belongs to the mobile device or the UE and is known to the network, DevID, by extracting a Type Allocation Code, TAC, and a Serial Number, SNR, from an International Mobile Equipment Identity, IMEI, of the mobile device or UE; when using the TAC and SNR omitting the spare digit of the IMEI for a total of 14 digits; placing a namespace ID and the DevID in network byte order; concatenating the namespace ID and the DevID; computing a hash of the concatenated string using the selected hash algorithm; setting fields of a Universally Unique Identifier, UUID, using the hash and creating a string representation; and placing the string representation in an urn form by pre-pending "urn:uuid" to the string so as to construct the Instance ID as a UUID, URN using the string representation of a UUID. creating an Instance Identifier, ID, to uniquely identify the mobile device or the User Equipment, UE, in the communications network whilst ensuring the privacy of existing mobile device or UE identities, wherein the creation of the Instance Identifier is based on: selecting a hash algorithm from one of MD5 or SHA-1; creating a Unique identifier that belongs to the mobile device or the UE and is known to the network, DevID, by extracting a Type Allocation Code, TAC, and a Serial Number, SNR, from an International Mobile Equipment Identity, IMEI, of the mobile device or UE; when using the TAC and SNR omitting the spare digit of the IMEI for a total of 14 digits; placing a namespace ID and the DevID in network byte order; concatenating the namespace ID and the DevID; computing a hash of the concatenated string using the selected hash algorithm; setting fields of a Universally Unique Identifier, UUID, using the hash and creating a string representation; and placing the string representation in an urn form by pre-pending "urn:uuid" to the string so as to construct the Instance ID as a UUID, URN using the string representation of a UUID. selecting a hash algorithm from one of MD5 or SHA-1; creating a Unique identifier that belongs to the mobile device or the UE and is known to the network, DevID, by extracting a Type Allocation Code, TAC, and a Serial Number, SNR, from an International Mobile Equipment Identity, IMEI, of the mobile device or UE; when using the TAC and SNR omitting the spare digit of the IMEI for a total of 14 digits; placing a namespace ID and the DevID in network byte order; concatenating the namespace ID and the DevID; computing a hash of the concatenated string using the selected hash algorithm; setting fields of a Universally Unique Identifier, UUID, using the hash and creating a string representation; and placing the string representation in an urn form by pre-pending "urn:uuid" to the string so as to construct the Instance ID as a UUID, URN using the string representation of a UUID.