It is unlikely that all mobile banking/payment subscribers in the world will be served by one deployment. This is not practical and will be highly unlikely (if not impossible) given the current state of success in the markets. It is just not conceivably possible that all Smartmoney subscribers in the Philippines will all be converted to MTN Mobile Money system hosted in South Africa. In all the countries where mobile money deployments are successful, many (or at least more than one) deployments can be found.It is therefore important to consider how subscribers to different mobile payment networks would be able to make payments to subscribers on other networks. Cellphone users are accustomed to phone subscribers on other networks. It stands to reason that they would expect to be able to pay subscribers on other networks. Unfortunately this is an extremely tough problem. Anyone suggesting a "easy" solution to this interoperability problem should not be taken seriously. The problem is multi-dimensional. A workable solution will have to consider many of the following aspects: technological problems, clearing and settlement challenges, legal and regulatory, consumer protection (including mechanisms to cater for disputes, warrenties and claims). The problem is almost unsurmountable.
So what is the way forwards? For a start one will be seeing many point-to-point solutions. (Two installations allowing bi-lateral agreements between each other). It is essential that interoperability is tested and experienced in these one-on-one situations first. We at Fundamo have now deployed sufficient installations running our technology (more than thirty) that make these one-on-one interoperable situations possible. After we see success with these, expect more complex network interoperable deployments to start appearing.
Also expect the industry to start working on solutions that will drive interoperability. A recent announcement in this regard is relevant.