When will three have 4G access?

I have a iPhone 5 with three but I don't have 4gee I'm wondering when they will upgrade to the new 4g as three say it will be free to all customers. My 3G has been slow on my phone.

3 haven't published a date yet, they just say that 4G will be coming "later this year".
I would keep an eye out on their website, it will give you updates on when 4G will come to your area.
http://www.store-3.co.uk/3-mobile-4g-network.html