Input (grade 13): The BT postcode area, also known as the Belfast postcode area, Royal Mail, Address Management Guide, (2004) covers Northern Ireland and was the last part of the United Kingdom to be coded, between 1970 and 1974.
Output (grade 4): Northern Ireland was the last part of the United Kingdom to get post codes. The BT postcode area was made between 1970 and 1974.