The company is seeking an agency that can create campaigns, at a local and national level, which will boost its funding projects.
Stop Funding Hate, the campaign group which calls on brands to divest their advertising spend from certain media outlets that it thinks promote prejudice, is one project currently featured on the site.
Crowdfunder said the successful PR agency must also be "excellent at traditional PR".
A spokesman for the company told PRWeek it currently has more than 20 regional campaigns and more than 10 national campaigns live on its site. As such it is "particularly interested in hearing from talented regional agencies" that are already aware of the concept of crowdfunding and understand the benefit it can bring, the statement said.
The successful agency will also be tasked with discovering new funding partners, Crowdfunder added.
Interested agencies are being asked to express an interest via the Crowdfunder site by 19 March, and the successful agency will be announced on 18 April, with work to begin thereafter.
The spokesman said: "We are looking at a retainer between £2,000-£4,000 per month, including additional campaign-specific work."
The brief is for an initial period of six months and will be renewed for ongoing work thereafter, he added.
In 2016, the UK-based crowdfunding platform raised £16.5m across 6,340 projects. According to crowdfunding market intelligence service Crowdsurfer, the next largest UK-based rewards crowdfunding platform, Fundsurfer, raised £250,000 for 35 projects.
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