How do I restore a company I archived?

Go to Tenant Management and open the recovery window (the trash/archive view). You will see archived companies with the date they were archived and when their recovery window ends. Click Restore on the company you want back. It returns to the active list with all its data, users and settings intact. Restoring is always available while the company is still inside its recovery window. Only after the window expires can a company be purged (permanently removed), and that is a separate, PIN-gated action.