About 440,000 Commonwealth Bank customers have attached an NFC sticker to their iOS phones since the bank started offering the PayTag stickers for contactless mobile payments in late 2013.Those customers use their phones about 600,000 times a month to make contactless payments - a little over one transaction per customer per month.CBA group executive for retail banking services, Matt Comyn, said the transaction rate for Android smartphone users, where the transactions is transmitted through an embedded NFC chip, was similar.CBA's mobile banking rollout has been a big success for the bank, with 3.9 million app downloads and A$4.6 billion of transactions on the app per week.Clearly, contactless mobile wallet payments are not a big part of that success story but the bank is committed to pushing ahead with the technology.CBA offers a proprietary mobile wallet and has said it will offer Android Pay. Its subsidiary Bankwest launched it this week.Comyn said the bank was working on a resolution of its differences with Apple. He said the argument about access to the NFC chip in the iPhone was not about interchange fees."We want the same experience for customers using the bank app as Apple Pay," he said.In the meantime, CBA is working on a number of improvements to its digital and mobile services. In September it added a bill tracker feature to the app and has had 2.3 million views since then. On Friday it will go live with a credit limit manager, which allows customers to use their phone to make temporary or permanent changes to credit card limits and impose spending caps.It is an extension of the bank's lock and limit facility, which is one of the most popular features of its app.In two weeks it will add a contactless card lock and it is adding a "camera pay" feature that allows a payment to move from one CBA customer to another by using the phone's camera to manage the transfer.