New technology is being developed which will simplify how users top up their Leap Cards.

The National Transport Authority (NTA) says the new system will enable cardholders to add credit through a smartphone app - from their credit or debit cards - by holding the card and phone close to each other.

Other features of the app will let people collect tickets they have bought online without having to visit a ticket machine, and also to check their balances in real-time.

At present, users can only check their Leap Card balance on the website for the previous day.

A contract has been awarded to the company ViX to develop the new features, which will be launched over the coming year.

Gerry Murphy, CEO of the NTA said: "These exciting new features will take significant development time and will be released in stages but we wanted customers to know that we are tracking the fast-moving technology field and will continually incorporate improvements and changes into Leap."

"The recent incorporation of NFC on iPhone 6 means that what we develop will be available to the full smartphone community," he added.