Apple is about to embark on a big expansion of its Apple Pay service in Australia, after signing a deal with payment services provider Cuscal. Thirty-one of Cuscal's clients will launch Apple Pay in coming weeks.Participating institutions include Bank Australia, Bank of Sydney, Beyond Bank, CUA, Defence Bank, MyState Bank and The Rock, People's Choice Credit Union, Police Bank, QT Mutual Bank, Teachers Mutual Bank and UniBank.They will join American Express, which went live with Apple Pay last November, and ANZ, which launched in April.ANZ chief executive Shayne Elliott told investors at the bank's 2015/16 results briefing last week that customers had conducted five million transactions using the bank's digital wallets (ANZ also offers Android Pay and a proprietary service called ANZ Mobile Pay). Elliott said customer acquisition was at an all-time high, with September the best month ever. He put this down to the appeal of mobile wallets and other digital services.Cuscal chose to complete its agreement with Apple rather than wait for the outcome of an application by three of the big banks and Bendigo and Adelaide Bank to the Australian Competition and Consumer Commission for approval to negotiate collectively with Apple.Among other things, the banks want the right to decide whether to pass Apple's fees on to consumers and they want to be able to provide competing mobile wallets "without Apple unreasonably impeding or preventing this."Cuscal clients have been able to offer Android Pay since July. Google has an open engagement model for Android Pay, which means it is not taking a cut of the transaction fees.Cuscal clients offering Android Pay have told Banking Day the service is popular with customers.