Entertainment company Sky has announced what it’s calling “the UK's most flexible mobile service”. Customers with another Sky service will be able to sign up for Sky Mobile from mid-December, with a full launch expected in early 2017.

Sky TV customers will be given free UK calls and texts with any Sky Mobile plan. In addition, their Sky box will automatically synchronise with an app on their phone, allowing them to watch recorded television shows on the move.

Unlike the UK’s major networks, Sky Mobile will let customers save any unused part of their data allowance at the end of the month. This will be available for up to three years whenever the customer needs to use it. They’ll also be able to change tariff every month.

Contracts run for a minimum term of 12 months. There are three data plans: 1GB for £10 per month, 3GB for £15/month and 5GB for £20/month. Unlimited calls and texts for non Sky customers are available as a £10 per month option.

Stephen van Rooyen, Chief Executive of Sky UK and Ireland, said “We felt it was time to shake up the mobile market and give customers a completely new way to manage their mobile plan – something no one else is offering. We’ve designed it based on what people told us they want – it’s easy, flexible and transparent and it puts the customer in control. With £2 billion being wasted each year on unused data in the UK, Sky Mobile customers will only pay for what they use. Plus we’re giving Sky TV customers a fantastic offer which will allow them to get even more value from their subscriptions. It’s time for people to have a smart new way to manage their mobile contract.”

Sky announced O2 (Telefonica UK) as its virtual mobile network partner in 2015.

Dan Howdle, Director of Communications at Cable.co.uk, said "Sky’s huge customer base will almost certainly ensure it will make up rapid ground on market incumbents. Sky’s ‘hook’ is allowing customers to ‘piggybank’ data that went unused at the end of each month and store it for up to three years. No mobile provider has ever offered this before. It shows a keen understanding of how customers consume their data – some months they use a lot, others they use very little. This flexibility should allow consumers to choose a lower data tariff on the basis of rolling over data they don’t use during lower-usage months – and that will save them money. Perhaps best of all, though, it may force the hand of other UK providers to follow suit – and that would be good for everybody.”