There's now more choice for ethical consumers as networks have opened up. Companies can now buy airtime from existing mobile operators, effectively piggybacking on their networks. The following brands operate this way: Phone Co-op (T-Mobile), Virgin (Orange) and Talk Talk (O2).

Only O2 (owned by Telefonica) receives a best rating from us for its environmental reporting. Vodafone was the recipient of a UK-government grant to pilot and launch a mobile banking scheme in Kenya, called M-PESA. The scheme provides people who can't afford — or are too remote to access — a bank account, the facility to transfer or receive money. Whilst a great initiative, it's highly unlikely that Vodafone would have taken the move without the government funding.

Standing out in our ratings with its particularly poor ethiscore is the "3" brand. It's owned by Hong-Kong billionaire Li Ka-shing's Cheung Kong group. Various interests include oil and gas exploration, oil pipelines and refineries and a shipping port in turmoil-ridden Burma.