Three payments providers will be allowed to merge despite concerns charges for electronic transactions could later rise.
BPAY Group, Eftpos Payments and NPP Australia will join forces after the Australian Competition and Consumer Commission on Thursday allowed the bid.
BPAY allows bills to be paid. Eftpos lets people pay by card. NPP allows real-time payments.
Opponents of the merger are concerned about what may happen to the Eftpos service.
In many cases Eftpos provides a cheaper alternative to using the Mastercard and Visa networks.
To allay these concerns, the payments providers have pledged Eftpos will continue to be available for at least four years. Users will continue to be able to choose the least costly network.
The ACCC has accepted the pledge, which can be enforced by a court.
The Reserve Bank will also ensure those making payments can choose which network they use.
ACCC chair Rod Sims said rapid change was happening in payments and the ACCC was satisfied the merger would not have an adverse impact on Eftpos services.
Robert Milliner, the chair of a payments group representing the providers, said the merged group would better compete with international card operators and technology giants.
Apple and Google's popular digital wallet services on phones have given them increasing clout over the future of payments.
The big four banks are the major shareholders of the three payments providers.
Mr Sims said they would be more likely to invest in domestic payment services if the companies merged. This would bring benefits to Australians, he said.
The three providers will maintain their identities and call their combined efforts Australian Payments Plus.