Service designers use different prototyping techniques to create representations and visualizations of future services. These prototypes can allow whole or parts of services to be experienced and evaluated. The approach and technique used to prototype by designers is influenced by when prototyping occurs in the overall design process and what the purpose is. Important perspectives for prototyping are discussed in the chapter on three levels: stakeholder, activity and prototype. Examples of two projects where service prototyping techniques (desktop walkthrough and service walkthrough) were used are described and discussed in relation to the service prototyping perspectives introduced in the chapter. The examples illustrate how prototypes can be used during service development and more specifically how they embody progression, promote collaboration and build trust across different stakeholder groups.