From August 29, three of the four major carriers in the UK will have flipped the switch on 4G LTE. But, the one many are perhaps waiting for is Three – they'll be using some 1800MHz spectrum supported by the current iPhone 5 – and they've re-confirmed their plans for a Q4 launch, and that they won't be charging extra for it in a statement to Coolsmartphone:

We’re on track to launch in Q4 and we will offer 4G at no extra charge. When we switch on our 4G network well over a million of our customers will already have a 4G device, so they will get automatic and hassle-free access in 4G areas without the need to change plans or sim cards.

Everyone on Three with a 4G device will be able to enjoy our 4G services as we roll out the network across the country to add capacity to what is already the UK’s fastest 3G network.

Three already offers impressive speeds on their HSPA+ network, often coming close to EE's 4G LTE data speeds, so the excitement is understandable. As it stands, you should be able to continue using your iPhone 5 as always and when they flip the switch, 4G LTE will just magically appear. No new SIM, no new plan. If you're on the One Plan, like I am, that should mean unlimited 4G LTE data as well as tethering. Then of course, we should also have a shiny new iPhone by the time they're ready to launch as well. Who's holding out for Three instead of moving?

Source: Coolsmartphone