Network service version management techniques are disclosed. Service access information, which is associated with access to a network service by a network service user, may be destined for a particular version of the network service. A determination is made as to whether a different version of the network service is accessible by the network service user. If so, then a further determination is made as to whether to select the different version of the network service to process the service access information. Any inconsistency between versions of the network service, such as different information requirements, can be handled by transforming received service access information. A replay function may also be provided, to have service access information again processed by the same or a different version of a network service. This function may be useful, for example, where a version of a service is rolled back or for debugging.