The charity, formerly known as Child of Achievement, rebranded as Wavemakers last October to distance itself from the resignation of its trustees over unauthorised payments. Its CEO is Deborah Skillicorn.
The Drum Consultancy was hired to raise its profile but has been replaced in the run up to the charity's inaugural Achievement Awards, which take place on 28 April.
Storm Communications, which won the account without a competitive pitch, will take over as Wavemakers' retained agency.
Storm will be expected to build awareness of the charity's work with children and increase recognition of the Wavemakers brand among the public in a bid to attract sponsors.
It will publicise the awards, which celebrate the extraordinary achievements of children who have empowered themselves and others in areas of social care, education and health, to national and regional media.
The agency will also look to encourage more support from celebrities for the awards and for the charity on a long-term basis.
Other media targets include young people's, women's, charity, education and local authority press.