BT has launched SmartTalk, a free app which enables users to make calls on their iPhone on the price of a landline call.

Up to 5 users can register to a single BT account, and use the OTT app to make mobile calls, over a knowledge connection, that are then billed to their home phone calling plan, and charged accordingly.

This implies that calls from abroad made via the app could be treated as UK calls, that may potentially make it free – so long as the user is hooked up to wi-fi and never using up roaming data to make the decision.

SmartTalk also provides another option to the problem of calling 0800, 0845, and 0870 numbers from a mobile, that may charge up to 50p per minute despite being free for landline callers.

Over the last year or two, loads of parties have launched mobile-friendly voice shortcodes, but that solution requires brands to take responsibility for establishing shortcodes. While the SmartTalk app is basically a piece-around, it puts this power within the hands of shoppers.

“This is a very exciting breakthrough meaning you may take your BT calling plan with you and continue saving money when you’re clear of home, either within the UK or abroad,” said John Petter, managing director of BT Retail’s consumer division. “BT SmartTalk helps you get much more value out of your BT package and lots more out of your smartphone. Ultimately it is easy to call freephone 0800 numbers at no cost from mobiles and get inclusive 0845 and 0870 calls too. And naturally, you could make the most of BT wi-fi which supplies you access to an enormous network of seven.5m hotspots world wide.”