This would be particularly useful when importing company details from companies house. the system can offer a collection of addresses in the same postcode area, and their is no way to check who is currently using an address.
It would also/as an alternative be useful to select the "Agents' address"
Guest
It is possible to view the 'usage' of an address. If you go to File / Search / Addresses and search Postcode, Town or County, then View an address there is a Usage button to view which clients are attached to that particular address. The agent's address will also be included in this list.
Future consideration: to offer this option when importing from Companies House