Yes, however, we do NOT recommend doing so. Each user account is unique and personalises itself according to your user behaviour. Features such as “suggested projects” (construction projects that are of interest to you based on your user behaviour) will be much less accurate.
It is possible to log into your user account from different device types (e.g. desktop computer, mobile) at the same time. However, the same user account cannot be used to log into two or more devices of the same type. One user account can only be used at the same time on the same device type.