User registration can have a serious impact on the success of online government services. Different services require different levels of identity assurance, and different registration processes are put in place to deliver them. But from the citizen’s perspective, these processes often require a disproportionate amount of effort, which reduces users’ acceptance. Typically, when sign-up to high-effort services is not mandatory, take-up is low; when it is compulsory, it causes resentment, and neither is desirable. Designers of services requiring registration currently have no way of assessing likely user acceptance at design time. We are introducing a tool that allows system designers to identify the impact of registration processes on different groups of users, in terms of workload and friction. Personas have been successfully applied to assist security designers, and we extend the concept with statistical properties, and introduce the Persona Group Calibration (PGC) exercise to calibrate the different personas for sensitivity to specific identity-related elements.