Follow the steps below to reactivate an Other Office.
Select Customer Setup > Practices.
Use the Show All button to view all practices. Or use the Search field to further drill down your search.
Select the Practice.
Locate and click on the Other Offices tab from the right-hand side panel.
Place a check in the Show inactive offices box
Select the Other Office you want to reactivate.
Uncheck the Make this office inactive box.