Many international banks require that account numbers be specified in a particular format. See below for details.
CLABE (Clave Bancaria Estandarizada or Standardized Bank Code) is a standard for numbering of bank accounts in Mexico. The CLABE account code has 18 digits, and is a requirement for the sending and receiving of domestic interbank fund transfers.
Canada: Transit Number
Canadian transit (branch) numbers have the following form: XXXXX-YYY
XXXXX is a Branch Number, and YYY is an Institution Number. The dash between the Branch Number and the Institution Number is an integral part of the code format.
Australia and New Zealand: Bank State Branch
A Bank State Branch code (abbreviated as BSB) is a six-digit code used in Australia that identifies an individual branch of a financial institution.
An almost identical system is used in New Zealand, with a six-digit BSB code, often split into a two-digit "Bank" code and a four-digit "Branch" code. However, the New Zealand and Australian systems are incompatible.
Various Countries: IBAN and SWIFT
The International Bank Account Number (IBAN) is an international standard for identifying bank accounts across national borders with a minimal risk of propagating transcription errors. An 8 or 11-character SWIFT code is required in conjunction with the IBAN.
Countries that commonly use IBAN
France, Germany, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom
Other countries with IBAN infrequently processed
Albania, Andorra, Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Dominican Republic, Estonia, Faroe Islands, Finland, Georgia, Gibraltar, Greece, Greenland, Hungary, Iceland, Ireland, Israel, Kazakhstan, Latvia, Lebanon, Liechtenstein, Lithuania, Luxembourg, Macedonia, Malta, Mauritania, Monaco, Montenegro, Poland, Romania, San Marino, Saudi Arabia, Serbia, Slovakia, Slovenia, Tunisia, Turkey, United Arab Emirates.