There are no commercial terms and conditions for these auctions. You just have to do the right thing: if you bid and you win then you have to pay. It is your responsibility to check that the people running the auction are bona fide and raising money on behalf of registered charity before you bid. If you are not sure then don't bid.
Bidsonline does not collect any money on behalf of the charity. If you are the winning bidder the money should be paid to the people running the auction or the registered charity.
Bidsonline provides a free service to help charities raise money and has no responsibility to you, the bidder. When you register and login to bid you agree to accept this.