Mobile data has never been more important, and it’s now no longer merely part of most mobile phone contracts, it’s usually the key selling point. Unlimited calls and texts are almost the norm, meaning big data allowances are how most providers try to differentiate their plans - not surprising given that the latest Ofcom survey found that web browsing was the single most important activity that people in the UK use their phones for.

That explains why data allowances with most smartphone plans are getting bigger and bigger, but plenty of users are so worried about running out of data that they end up paying for far more than they really need. One study from Kantar Worldpanel found that UK phone users waste an average of £100 each year on data that they don’t end up using.

That’s why Sky Mobile plans are all about helping customers make the most of their data, letting you roll all un-used data over for up to three years, so it doesn’t go to waste. Sky says that so far it’s saved its customers over £26 million worth of data since the launch of the service, which sounds like quite a lot to us.

The way it works is pretty simple. At the end of every month, Sky automatically takes whatever data you didn’t use and transfers it into your ‘Sky Piggybank’ - a big data store in the cloud that you can tap into whenever you like. Any month when you find yourself running low on data - or know ahead of time you’re likely to use up a lot - you can move a GB or two back out of the Sky Piggybank and onto your SIM just by heading to ‘My Sky’ on either the website or app.

It gets even better if you have a shared Sky Mobile account for your family. You can have up to five SIM cards share the same Sky Piggybank, meaning you can share data around the family. If one of you never manages to use up your allowance but someone else is hitting the data cap every month, sharing data with Sky Piggybank could help you save money across the family’s plans. If you’re already a Sky TV customer you’ll also be able to talk and text for free on any Sky Mobile plan, saving £10 a month in the process.

You can get even more flexibility thanks to Mix, a Sky Mobile feature that lets you tweak your plan each month to mix up your data, calls and texts, giving yourself more of whichever you think you’ll need most each month, while making sure that you only ever pay for what you need. Combine it with the data roll over, and you’ll see you get a lot of flexibility. You can max out your data on Mix and grab an extra GB from the Sky Piggybank if you know you’re going big on downloads, or use Mix to up your minutes, while using the extra data in your Sky Piggybank just in case you run low.

If you opt for one of Sky’s Swap plans, you get even more options. It’s not just your monthly plan that’s flexible: you get to swap your phone every year too if you want if you opt for Swap12, perfect for the Apple obsessive who just needs the latest iPhone every single September. Sky will even send you your new phone first, letting you get all set up before you have to send your old handset off, at which point they’ll evaluate how much it’s worth and credit your Sky account with the appropriate amount.

As you’d expect, plans and price vary a bit depending on what phone you opt for. One of the best offers is for the Apple iPhone X, which existing Sky TV customers can get with no upfront cost, unlimited calls and texts, and 500MB monthly data for just £42 per month on a Swap24 contract. Sign up right now, and Sky will even throw in a free return flight to Europe as part of a special offer.

If you’re tired of one-size-fits-all phone contracts and want something flexible enough to keep up with you - not to mention that can help you save a bit of money along the way - check out the new Sky Mobile plans and see if any fit the bill.