The account covers all of the service’s marketing activity, which was worth around £14 million in 2012.
Inferno’s appointment follows a contested pitch run through the Government Procurement Service.
DLKW Lowe, the incumbent on the account, was picked to launch the service in 2011 and is understood to have repitched.
The Money Advice Service pitch is the first to be completed through the GPS since the new creative roster was announced in February.
The other agencies on the roster are Abbott Mead Vickers BBDO, DLKW Lowe, Engine, Enter, Kindred, M&C Saatchi, McCann London, Rainey Kelly Campbell Roalfe/Y&R and Ogilvy & Mather Group.
Other pitches currently being handled by the GPS include one for the Department for Transport’s Think! campaign, which has been with Leo Burnett since 1979.
The Money Advice Service and Inferno declined to comment on the appointment.