Disadvantaged and isolated communities in some of the world's poorest regions will be hit hardest by moves to shut down international money-transfer businesses.
Banks claim the moves are in response to fears over terrorism financing.
Remittance businesses in Australia help about two million customers send $30 billion a year to recipients in more than 150 countries.
Usually, it is in small sums, done cheaply, swiftly and without the need of a bank account.
In some cases, money is hand-delivered to people in remote areas.
Ioane Lafoai of SBS Radio's Samoan program, sends money back to his family in Samoa through such offices.
"They're a lot more efficient. If you want money to be sent to an outer island in Samoa, they will have an agency there. The bank wouldn't."
But the major banks are closing the accounts of international money remitters.
The Australian Bankers Association's Steven Munchenberg says it is in line with international laws to combat terrorism funding and money-laundering.
"Now what these rules mean is that, when we send money overseas, we have to know where that money has come from and where it's going. Now, unfortunately, when we're dealing with remittance agents, we don't always know who all of their customers are, and we don't always know where all the money is going."
Remitters say the businesses will be driven underground.
Dianne Nguyen's family started its remittance business in the late 1970s in Sydney's west-suburban Cabramatta.
She is now director of the Remittance and Currency Providers Association.
"Every transaction that we conduct is reported to Austrac, who is the regulator, and they see every single dollar that goes anywhere. If that transaction now goes underground, then that won't be reported, and there will be no visibility."
Remittance providers are able to offer rates lower than the major banks but are almost all dependent on banks to make transfers.
Ramanathan Karuppiah has seven remittance offices across Brisbane and Darwin.
He sees the banks' motives differently.
"The Australian banks are trying to chase the competition away, based on their profits. But, in my opinion, this is not the right approach."
Sydney Liberal MP Craig Kelly has raised the issue in federal parliament.
"We know this is a $60 billion industry. We know that these private operators do it at a lot less cost than the banks. In rough sums, if even half of the business is transferred from the private remitters to the banks, it works out at an additional $1 billion worth of profit to the banks."
Both sides are urging regulators to work with their international counterparts on a global framework to allow banks to continue working with remitters.
