More than 750 fundraisers from across the country attended the conference, organised by fundraising consultants Action Planning in association with chief executives body Acevo.
Many of the speakers told stories of disgruntled donors who had not been thanked by charities after giving large sums.
Dame Stephanie (Steve) Shirley, who sits on both sides of the fence as an entrepreneur and donor, as well as a fundraiser for her autism charity the Kingwood Trust, said: "Donors don't give to be thanked, but we certainly notice when we are not."
Beth Breeze, deputy director at the Institute for Philanthropy, said it was vital to let donors know what happens to their money after they give, however big their donation.
She related the experience of one donor who raised £30,000 for a charity and didn't hear anything. She telephoned and was told: "Oh, I'm glad you called; we wanted to say thank you."
Other speakers included: Lord Robert Gavron, founder of St Ives plc and a major donor; Dr Philip Beresford, author of the Sunday Times Rich List; and Simon Craft-Stanley and Wendy Baverstock, both from Action Planning.