Currently, the B1 district has about 300 postcode units spread across 3 geographic postcode sectors.

The World Snooker Championships at the Crucible Theatre, Sheffield; [60] 147 UP refers to a maximum lead (from a maximum break) in snooker Further information: List of postcode areas in the United Kingdom, List of postcode districts in the United Kingdom, and List of post towns in the United KingdomExamples of Norwich NOR postcodes in the old format: "NOR 03Z", "NOR 66F", "NOR 83B", "NOR 05S". "No. 45542". The London Gazette. 13 December 1971. p.13658. In 1917, Dublin—then still part of the United Kingdom—was divided into numbered postal districts. These continue in use in a modified form by An Post, the postal service of the Republic of Ireland. In 1923, Glasgow was divided in a similar way to London, with numbered districts preceded by a letter denoting the compass point (C, W, NW, N, E, S, SW, SE). [4] Postcode areas are also divided into several post towns, which predate the introduction of postcodes, with the London post town uniquely covering more than one postcode area. Lloyds TSB – Frequently asked questions". Lloydstsb.com. Archived from the original on 16 June 2012 . Retrieved 31 July 2012.

The only letters to appear in the third position are A, B, C, D, E, F, G, H, J, K, P, S, T, U and W when the structure starts with A9A. If the Information Provider does not provide a specific attribution statement, you must use the following: Certain British Overseas Territories introduced single postal codes for their territory or major sub-sections of it. These are not UK postcodes, even though many are formatted in a similar fashion:The postcodes are alphanumeric, and are variable in length: ranging from six to eight characters (including a space). Each postcode is divided into two parts separated by a single space: the outward code and the inward code respectively. The outward code includes the postcode area and the postcode district, respectively. The inward code includes the postcode sector and the postcode unit respectively. Examples of postcodes are "SW1W 0NY", "PO16 7GZ", "GU16 7HF", and "L1 8JQ".