Given that technology has shrunk the world, it's common practice for people to buy something from the other side of the world on a daily basis. However, each country has its own financial system. Some things translate easily, and others are just curiosities to outsiders. Sort codes on debit cards are one of these curiosities.
A sort code is a unique number given as a kind of address for bank branches in the United Kingdom. Sort codes are used internally by the bank for identification purposes. Rather than writing out the bank's physical address, sort codes identify different bank branches instantly. A sort code appears on a bank customer's personal checks, debit card and statement.
Debit cards issued by banks in the United Kingdom are 18 digits in length. The sort code for the card holder's bank branch may appear between the first four digits, which indicate the card type, and the last eight digits, which identify the account number.
A sort code is given as six figures, viewed as three sets of two with hyphens in between them. An example of a sort code would be 83-17-49.
Some people are under the mistaken impression that a sort code is unique to each account holder. A sort code is meant to identify the bank branch of the customer's account. This is why both numbers are often used in conjunction for transactions in the United Kingdom.
A sort code is not permanently assigned. If a customer changes her bank branch, the sort code will be changed to reflect the new branch where her account is being held and used.