Xfinity Mobile is a Comcast subsidiary that runs a virtual mobile network using Wi-Fi hotspots and Verizon’s cell network. Whatever you might think about Comcast’s home internet or cable service, Xfinity Mobile is actually great value for money, especially for big families with a mix of different users.

But for the first year of its existence, Xfinity Mobile has been difficult to join. It’s only available to customers who have one of Comcast’s other services, like cable TV or internet, and you had to buy a new iPhone from Xfinity Mobile in order to sign up. The existing Comcast customer hasn’t gone away, but starting now, you can bring your own iPhone to the network, which makes switching over that much easier.

The change is simple: any unlocked iPhone 5 or newer that works with Verizon’s network is eligible, which covers most iPhones currently in use on Sprint or Verizon’s network. Thanks to the two different kinds of mobile networks in the US, GSM and CDMA, iPhones purchased directly from T-Mobile and AT&T likely aren’t compatible with Verizon’s network, so you can’t bring them to Xfinity Mobile.

There are two plans on offer: the $45-per-month Unlimited, which gets you unlimited talk, text, and data, up to a soft cap of 20GB per month; and the per-GB option, which charges $12 per GB per month.

Comcast is letting you mix and match different types of line on one account, which is unusual for a wireless carrier, and can help make a family plan a lot cheaper. Normally, pricing for Unlimited plans works that the cost per line decreases the more lines you have on the account, but you can’t mix and match different types of lines. It’s designed so that you’ll end up paying for unlimited data for you entire family — even your grandparents who still have an AOL email — since it’s cheaper than doing it line by line.

With Xfinity Mobile, you can pay $45 for any heavy data users in your family, and $25 a month for those who just need a few gigs of data. In theory, it could be a lot cheaper than doing it through T-Mobile or Verzion — and you’re getting Verizon’s excellent network to boot.

“With the introduction of BYOD, we now have a convenient way for iPhone users to switch to Xfinity Mobile and get access to the best 4G LTE network plus 18 million WiFi hotspots without having to purchase a new phone,” said Rui Costa, vice president of product management and customer experience for Xfinity Mobile. “A core tenet of Xfinity Mobile is that it’s simple and easy, and our in-store BYOD experience will be no different,” added Costa. “We are committed to simplifying the mobile experience from the moment a customer signs up, through activation and account management.”