The company has secured 28 special-build, extra-large sites to support the TV campaign, starring Ricky Tomlinson, which will break on 9 October. The media planning and buying is through Carat.
A poster in Leeds reads: "Cut your bills", with the message cut in half and spliced on to two adjacent buildings. Another poster in Nottingham has been posted upside down and reads: "Because things go wrong."
Nick Smith, the director of marketing and strategy at British Gas, said: "CHI looked at our business inside and out. What it found among our people was a strong desire to do the right thing for our customers, and that's where the campaign thought was conceived.
"'Do the right thing' also struck a chord with customers. It fits with our strategy of moving British Gas from a leading energy supplier to a leading home-services brand and is evidenced by putting the product and services benefit at the heart of the communication."
The television campaign, which drives home a customer-friendly message, was shot at British Gas' real-life training academy. The supervisor at the academy, played by Tomlinson, aims to make sure that "do the right thing" is part of the DNA of every British Gas employee.
The campaign was written and art directed by Brian Turner and Micky Tudor. The television ads were directed by Jesse Peretz through Cowboy Films.