Iran has been largely cut off from global commerce after the company that handles most international financial transactions said it was severing ties with 30 Iranian banks.
The action by the Society for Worldwide Interbank Financial Telecommunication (SWIFT) aims to enforce EU sanctions discouraging Tehran from developing nuclear weapons.
SWIFT is crucial to the oil sector and other trades and global financial transactions are impossible to conduct without using it.
Al Jazeera’s Harry Smith reports.