Britain: Zip Code Banking

British bankers have a reputation for being a stuffy lot. In the words of a Board of Trade commission, they run their banks "as a club for the benefit of members, not the public." They keep the most bankerish of bankers' hours, charge high rates for their services, and send their customers statements only once every three months. Small wonder that most adult Britons assiduously avoid checking accounts.

Soon, however, the bankers may have to start changing their ways. The reason is that they are being confronted by a competitor the likes of which they have never had before: Britain's...