NatWest and RBS customers can now get an instant access savings account on the move through a new mobile banking app.
iPhone customers were the first to be offered this option for Instant Saver and Cash ISA accounts late last year.
The banks says 112,000 savings accounts have been opened by customers on their mobile so far, and is now deploying the option as an automatic upgrade to its 2.7 million mobile subscribers.
Head of savings for NatWest and RBS, David Crawford, says: "Our customers are changing the way they bank with us. They want to be able to service their everyday banking needs - including saving for a rainy day - where and when it is convenient for them."