eBay’s CEO, John Donahoe, believes that digital payments should account for a lot more of the global payments market than they currently do.

One of the big ways he’s trying to make that happen is by ensuring his PayPal subsidiary grows its volume in the most promising digital payments space — mobile. On that front, it appears he’s making good progress as quietly, mobile payments have become a multi-billion dollar business for PayPal.

That, for obvious reasons, is probably not what bank executives want to hear. So it’s no surprise that banks and other traditional players in the finance and payments markets are getting involved in the most promising digital payments space.

One of them is Barclays, which has launched a new mobile payment offering called Pingit. As TheNextWeb describes, it can be used to send money directly to an individual using nothing more than a phone number:

Barclays says that Pingit is Europe’s first person-to-person service for sending money this way, requiring customers to own just a UK current account and a domestic mobile phone number. The service does away with bank details by linking a customer’s account to their mobile device.

The good news is that, whilst the ustwo-designed app is available to Barclays customers at launch, it will be made available to all current customers of UK banks and building societies, with full UK access expected to be rolled out by March.

The Pingit app is currently available for iOS, Android and Blackberry. Security is provided by a five-digit password and transaction limits, currently set at £300 per transaction and £5,000 per day.

While Pingit will initially appeal to consumers who want to engage in peer-to-peer money transfers, Barclays isn’t ignoring the opportunity to target merchants. Small businesses can also register to use Pingit, giving them the opportunity to collect payments without a credit card reader and POS system.

The big challenge, of course, is user acquisition. The mobile payments space is getting more and more crowded by the day, giving consumers plenty of options to choose from. Established institutions like Barclays are obviously hoping that their existing relationships with customers will enable them to drive usage of new offerings like Pingit, ensuring in the process that customers come to see them as one-stop solutions for all of their banking and payment needs.

To do that, however, companies like Barclays will need to get the customer experience just right. Mobile payment apps need to be easy to use, reliable, secure and interoperable with a wide variety of users, many of whom may be customers of other institutions. This will certainly be challenging but based on the growth of the mobile payments space and where it will likely be in five years, banks and traditional financial and payments companies have little choice but to try and meet the challenge.