It follows the organisation’s move to expand its services and develop its strategy.
The review kicked off in December with the help of AAR. The charity had chemistry meetings with four agencies and hired Fold7 without going forward for a pitch.
Fold7 will work on insight, brand and PR activity.
Diana Tickell, the chief executive at Nabs, said: "Fold7 were the standout due to their progressive and modern approach to communications.
"We are confident they will help us to strengthen and amplify our cause for the benefit of this vibrant industry".
Nabs was founded in 1913 and provides advice, coaching, financial assistance and career guidance to the ad industry.