Strong growth in consumer use of contactless payment technology has encouraged banks and service providers to push ahead to the next frontier - digital wallets in mobile electronic devices.Westpac reported last week that 54 per cent of its customers' debit transactions were now contactless. The industry has been surprised at the rate of take-up of contactless and is hoping to achieve similar growth with mobile wallets.In a research report published this week, EY said it asked consumers about their use of "money transfer services" on their primary mobile device. Among Australian respondents, 11 per cent said they used mobile payment services regularly (every day or several times a week), while 16 per cent said they used the services occasionally (about once a week or less).Fourteen per cent said they had not used the service but were considering using it in future.Seven per cent said they had used mobile payment services but no longer used them, while four per cent said they had tried the services but did not become a user. Forty-eight per cent said they had not used the mobile payment services and had no plans to use them (when asked about their use of mobile payment services at the point of sale, responses were similar).Regular users of mobile payment services said ease of use, value for money, security and privacy, and a trusted service provider were important considerations.User numbers are sure to grow. Seventy-three per cent of respondents to a survey commissioned by Commonwealth Bank and published yesterday said they expected mobile wallets to replace their physical wallet in the next seven years. By that time they expect to be paying for public transport, coffee and a range of other goods with an electronic device on a daily basis.Apart from making payments, consumers see mobile wallets as useful devices accessing loyalty schemes, redeeming coupons, and storing receipts , tickets and personal identification.Banks are hoping that the trust factor will put them in the forefront of this emerging market. Among respondents to the CBA survey, 44 per cent said financial institutions would be the most trusted providers of mobile wallets, 16 per cent said government would be the most trusted provider, 14 per cent said technology companies and 10 per cent said retailers.One issue holding back acceptance of new payment systems in the past has been confusion about the technology. That could still be a factor. EY said the universe of mobile payments services was expanding rapidly "as boundaries blur between payments, marketing and shopping services delivered via mobile"."Mobile payments" include point-of-sale payments, mobile web payments, and mobile wallets. Technologies include near field communication, QR codes and Bluetooth.