The financial services story in Africa has been dominated in recent years by M-PESA, the Kenyan mobile payments service.

But an there’s also a mobile banking story worth noting at First National Bank of South Africa.

FNB, as it is called, is doing an impressive 230 million mobile banking transactions per month. M-PESA, as a comparison, is generating around 45 million transactions per month at last count.

The FNB number was tucked away in an IBM press release promoting IBM’s new System z platform for mobile applications.

Reportedly, FNB “was looking for an opportunity to transform an entire continent through its most popular channel: the mobile device.” The bank created a series of mobile banking tools recently that “increased its transactions to more than 230 million a month.” It is unclear exactly what types of transactions are included in that total.

M-PESA, meanwhile, has begun to offer its service in Europe, starting in Romania, so its transaction volume could be headed up. Way up.

Another interesting note about FNB is that the bank apparently sells its own phones, reporting 145% growth since 2012 in “data bundles,” which seemingly include phones and plans. Safaricom, which created M-PESA, is a telecommunications company. Mobile is so important in moving money in Africa that banks and telcos are increasingly indistinguishable.

According to IBM, FNB has had to scale up its mobile banking platform to meet the demand.

“Mobile transactions have grown at an exponential rate as we expand our range of services, client experience and reach, far outpacing growth in traditional transactions,” said Jay Prag, Chief Information Officer, FNB.

We suggest you take particular note of the word “exponential.”