There are several reasons to remain allied to one mobile network operator or another. Loyalty rewards such as contract discounts and special upgrade terms aside, switching providers can just be a bit of a faff. UK telecoms regulator Ofcom doesn't want this to deter you from shopping around, which is why it's going to make the process of jumping between carriers a whole lot easier. It's been on Ofcom's agenda since last summer, shortly after the regulator introduced a greatly simplified way of switching between broadband suppliers. Today, Ofcom's announced its formal proposals, volunteering a couple of different options it's settled on to the hassle out of moving providers.
Ofcom won't be telling mobile operators what's what until autumn, after taking feedback on its plan into account, which is why it's proposing two methods of simplification right now. The first (and preferred) idea is to introduce a "gaining-provider led" process, which is exactly how changing broadband providers works now. All a consumer would have to do is to pick their new carrier, and that company will do all the legwork on their behalf, including advising them of their current provider's notice period and any outstanding charges.
The second, slightly less convenient option is to make requesting PAC codes easier and immediate, either online, by text or by phone. You need a PAC code to carry your mobile number over to your new provider, but typically, you have to call your current carrier, put a request in, and wait (often a day or two) for the code before giving that info to the network you're switching to. With immediate access to PAC codes, there will be much less back and forth, and you should only really need to make the one call to your new provider.
Either way Ofcom decides to implement simpler carrier switching, it should incentivise you to seek out the best deals as your contract approaches its conclusion. It should also have a knock-on effect on competition, too, with carriers being ever more mindful of the level of service and prices they offer when it becomes much less a chore for consumers to jump ship.