UPS recently ended a contract with the United States Postal Service and delivery changes are coming to some post office box users as a result.

Under the change, UPS Sure Post packages are now only being delivered by UPS drivers, a spokesperson for the International Brotherhood of Teamsters spokesperson told Supply Chain Dive. In the past, the final leg of these deliveries was made by the U.S. Postal Service; now, they will be handled by UPS after the Jan. 1 contract expiration.

UPS SurePost packages will be delivered by UPS drivers only after a contract between UPS and USPS expired this year.