A BIC runs in the order of a 4-letter institution name, a 2-letter country, a 2-character city, and a 3-character branch or department. The last three characters are optional, and an 8-character BIC without them refers to the head office or similar. When written as 11 characters, the head office or similar is shown as XXX1.
The BIC is used to address messages, route transactions, and identify parties, and it can be assigned to organizations that are not financial institutions2. The BIC is used mainly to identify financial institutions, while the LEI, another ISO identifier, is used mainly to identify the parties to a trade in OTC derivatives reporting3.