They sure can! And for good reason. Thimble requires clients to create their own Thimble accounts. This allows us to inform the client quickly and directly about updates, changes, or issues with their accounts and policies.
Having direct access to their account allows them to make changes on their own. This helps avoid delays that can possibly disrupt their coverage.
Of course, you can always instruct your client to notify you so you can make updates on their behalf.