Wonderhood Studios has won Three’s advertising account following a competitive pitch process.
The agency beat Mother and Uncommon Creative Studio in the review, which was handled by AAR up until the shortlist stage.
Wonderhood will begin work on the business in the coming weeks and has been briefed to create a new strategic brand platform.
Three split with incumbent Wieden & Kennedy London in May after 10 years.
Elaine Carey, chief commercial officer at Three UK and Ireland, said: "We’re delighted to bring Wonderhood onboard. From the outset, they understood our brand and impressed us with their strategic thinking and creativity. Together we share ambitions for success, creating relevant and standout work, which delivers brand fame, customer loyalty and business growth."
The advertising review followed a major restructure at Three in March that merged the customer and marketing teams. Chief marketing officer Shadi Halliwell, who had been with the company since 2017, left after delivering its latest 5G marketing campaign.
Carey, previously chief commercial officer at Three Ireland, moved to the same role in the UK to lead the newly combined customer and marketing team.
Alex Best, chief operating officer at Wonderhood Studios, said: "We are honoured and excited to be appointed to be working on this iconic brand. The Three team ran a fantastic pitch process in very challenging circumstances and we can’t wait to get going."