Work time and task registration is done in some form at most workplaces. It might be everything from writing down the times in a physical logbook to having dedicated software for time registration. Tracking time and how it is spent can be beneficial for both the employer and the employee. The goal of this thesis is to find out if it is possible to make time reporting accurate and easy on a mobile unit, this by using methods from the user-centered design toolset to create a prototype. To facilitate seamless time registering scannable tags are introduced into the system. During the thesis work 75 people answered a survey. Five of these people participated in a design workshop and evaluated the finished prototype. The survey examined general attitudes towards time registration, the current system used at their workplace and a proposal for a new system. The survey formed the basis for the requirements on the system. A design workshop was held where the participants had to realize these requirements in a paper prototype. The participants from the workshop tested the programmed prototype at their workplaces and evaluated it. They also evaluated the experience of participating in the design process. The result of the prototype testing indicates that time reporting can be made easy and accurate and that the NFC-tags that were used were an aid. The testers were of the view that user-centered design is a good toolset that when used correctly can be used to capture requirements well.