I have trashed a project in Zoho Projects but it is not deleted from Zoho Books. How do I delete it?

If the synced project has transactions associated with, it will not be deleted from Zoho Books, even if you delete it in Zoho Projects. The project will be marked as “Inactive” in this case.

If you wish to remove the project from Zoho Books, you will have to delete the transactions and then delete the project.