How to change the client associated with a project

Important note

Do not try to edit an existing client by changing their name/contact details on the new proposal because that will change the client's details everywhere, even on the previous proposal you duplicated this one from.

Open your proposal.
Click on the pencil icon in the top right corner of the estimate tab.
Scroll to the Change client section
Open the client dropdown and find a different client to attach to this proposal, or choose create a new client by clicking Create new at the bottom or clicking the + button on the top right.
Then save your proposal.
You may need to refresh the page, or leave the quote and re-open it to see your changes take effect.
Changing the client will not change the project address and project name. You will need to also change those manually if required.