O2 has ended it's four year partnership with BT Openzone, where its customer's enjoy free WiFi across 4200 out of the 5 million BT Openzone hotspots around the U.K. From July 1, 2013 any O2 customers wishing to use BT Openzone hotspot will have to pay for the service. O2 are ending their partnership with BT Openzone so that they can transition customers onto their own O2 WiFi hotspots.
O2's hotspots aren't quite as many as what BT Openzone offers. With 8,000 hotspots, they offering more hotspots than they got with the BT Openzone partnership. Let's hope O2 will expand these hotspots over the next coming months. You can currently get O2 WiFi at a variety of outlets - McDonald's, Costa Coffee, Subway and Cafe Rouge, to name a few.
If you won't be planning on using BT Openzone once the O2 partnership ends, be sure to change your WiFi settings or even remove an BT Openzone ones from your list.