The agency won a pitch for the UK element of the international project and will focus on building the profile of the campaign ahead of its launch in March and the week-long challenge itself in April.
Designed to draw attention to the 1.4 billion people around the world who have less than £1 per day to live on, the campaign is led by the Global Poverty Project and backed by charities including ActionAid, Oxfam, UNICEF and Save the Children.
Agency founder Max Dundas will head the account, reporting to Emily Burgess, marketing and comms manager for the Global Poverty Project.
Dundas said the aim was to turn awareness into participation.
"There are a lot of good causes out there and the challenge is to make this a moment that stands out and inspires people into action," he said.
"There are many ways to do this and we will be looking to use peer leaders, celebrities and journalists to help the cause."
This year, 5,500 people across the UK took part in the challenge, raising more than £1 million for good causes.