The onegreenpaperclip fundraising initiative was inspired by Canadian blogger Kyle MacDonald, who initially swapped the paperclip from his CV for a pen, but eventually ended up with a van, a recording contract, then a role in a film and - after 14 trades - a new house in Saskatchewan, Canada.
People who register for the onegreenpaperclip competition will each receive a green paper clip in the post. They then have a week to perform a series of trades to obtain the most "desirable final item possible".
The scheme is part of National Enterprise Week, which runs from 12 to 19 November.
At the end of the week, contestants will be given a further three weeks to sell the final item, with all proceeds going to Barnardo's.
The entrants who raise the 10 largest amounts will each win a prize.