When you integrate with GoProposal your BrightManager prospect will be updated to a client once a full proposal has been signed. 

The service will be switched on for the client in BrightManager, and their Proposal and Letter of Engagement added, all you need to do then is invite them to register for a portal by navigating to Clients > People > Not Registered on Portal. 

For information on how GoProposal's integration works Click Here