The company, which used to trade as Personal Fundraising Partnership, lost one of its biggest clients, WWF-UK, four weeks ago.
Company chairman Chris Coleridge said it had accepted money from charities in advance and would not be able to complete their work but would make sure they were fully reimbursed. The company is asking creditors to approve a scheme under which the money will be repaid over the next two years.
Andrew Nebel, director of marketing and communications at Barnardo's, said: "Open Air Fundraising does have debts to Barnardo's but we are hopeful they will be recovered. We've finished our programme with them so they are not too significant."
The company has written to creditors proposing that it continues to trade and 80 per cent of its profits go to an insolvency practitioner to pay off creditors. Open Air Fundraising's largest debt is to the Inland Revenue but it also owes money to around 30 companies. Coleridge said he expected creditors to agree. If the company was closed down, the Inland Revenue, which automatically takes priority, would be paid around ?xA3;30,000, but it was unlikely anyone else would get anything.
The company was established in 1997 and introduced face-to-face fundraising to the UK. Steve Andrews, head of consumer fundraising at WWF, said: "The company's position pushed us to make a decision but we had been thinking about cutting our investment in face-to-face fundraising."
Open Air Fundraising was previously part of Personal Fundraising Partnership, which operated both face-to-face and telephone fund-raising services.
Coleridge set the company up with his wife Jane Cunningham. He left in June 2001when he separated from his wife, but still owned 50 per cent of the business.
It was divided into telephone and face-to-face services earlier this year, with Coleridge taking over the running of the face-to-face service, renamed as Open Air Fundraising. Seven weeks later it found itself in severe financial difficulties but was saved by a group of unnamed private investors.
Coleridge said: "When I took over the company it was not in good financial shape but I believed I could turn it round. I put into place a restructuring process but the debts were too great."
He also cited increased competition in face-to-face fundraising at the same time as a levelling out in the market.