The organisation last September completed a review of the IMR Standard which was introduced in 2013 to avoid consumer "bill shock" due to high international mobile roaming charges.
In a statement, the ACMA said its review found the IMR Standard had reduced bill shock, with complaints falling significantly.
But, it said, data from the Telecommunications Industry Ombudsman indicated complaints had risen recently. Complaint numbers were still relatively low, but disputed charges could be high, indicating risks to consumers.
For example, the review concluded, providers could be given flexibility in the wording used to advise consumers about maximum charges for IMR services, and how the information was delivered.
The review also concluded that mobile network operators and mobile virtual network operators should continue to provide information to consumers when they landed in another country.
The ACMA said Communications Minister Mitch Fifield had agreed to its proposal to change the form of regulation from an industry standard to a service provider determination with a similar but more flexible set of rules.
The change would allow the ACMA to more easily update the existing the rules.