To edit the Client field:
- Go to Settings > Projects > Project Attributes and edit the Client attribute (A)
- In the pop-up dialog you can edit "Client" (B) to something else (e.g. "Customer)
- Optionally edit the Description field which is displayed in tooltips in the application
- If you use Basecamp and do not want Client name to be taken from the Basecamp primary company, choose Selected from the values below (D) which will instead use your own custom values, including multiple clients per project.