SWIFT codes are made of blocks of numbers with this structure: BBBBCCLLXXX

Eg. BANKIA SA's SWIFT, also known as BIC code is CAHMESMM where

• the first 4 characters are the code of the bank, in the example CAHM for Bankia
• the next 2 characters are the code of the country, in the example ES for Spain
• the next 2 characters are the location MM
• the 3 characters to the right, if they exist, are the code of the branch. If they are XXX, the branch is the central office or headquarters.