Westpac, which was the last of big four banks to allow the transfer businesses to use their banking facilities, told the small business operators in a letter last month that their accounts will be closed within weeks.
The move comes after warnings about the use of international money transfer businesses to finance crime and terrorism and a federal review of money laundering and counter terrorism laws.
Last week, the international money transfer firm in Lakemba owned by relatives of terrorist Khaled Sharrouf was shut down after it failed to explain millions of dollars in transfers to the Middle East.
A spokesman for Westpac confirmed the bank was reducing the services it offered to international money remitters.