Archived organisations can’t be linked to Estimate, Invoice or Purchase Order reports. To archive an organisation, navigate to the Organisation option in the Admin menu.
Step 1: Select the Archive button for the list item (next to the pencil edit icon):
Step 2: Confirm archive, the item will be hidden from the list OR Cancel the action, the organisation will not be archived and will remain in the list.

To restore archived list items, select the Show Archived button in the top right corner:

The archived items will be displayed, select the Restore button (next to the pencil edit icon):

Select Confirm to restore the item, the item will be displayed in the list OR Cancel the action, the item will not be restored, the item will remain inactive (archived). Select the Hide Archived button to hide inactive items.
