"BX :
The non-geographic postcode area BX has been introduced for addresses which do not include a locality: this allows large organisations long-term flexibility as to where they receive their mail. This postcode area is used by Lloyds Banking Group (BX1 1LT) and parts of the HM Revenue and Customs like VAT Central Unit (BX5 5AT) and Pay as You Earn (BX9 1AS). Lloyds Bank also use BX4. After splitting from Lloyds, TSB Bank uses BX4 7SB, the latter part of which, when written, looks similar to "TSB"."