DG16 Blackbank, South Ribble, Smithfield Postcode district DG16: 7 named streets and 5 live postcodes, in Cumberland. Streets A6071, Smithfield A74(M), Blackbank B7076, Blackbank B7076, Blackbank Gretna Loaning, Blackbank M6, South Ribble M6, South Ribble Postcodes DG16 5HT DG16 5HU DG16 5HZ DG16 5JA DG16 5JB Source: ONS Postcode Directory (live postcodes only) and OS Open Linked Identifiers for the streets.