The comments by Institute of Fundraising chair Richard Taylor came the same day as 17 leading UK charities including Cancer Research UK, Oxfam and Save the Children had a letter published in The Sunday Times pledging their support for changes to fundraising regulation.
Charity fundraising has been under the microscope in recent months following the death of an elderly volunteer for the Royal British Legion and two Daily Mail exposés - one about fundraising call centres, which led to the closure of a major fundraising agency, and another more recently around the selling of donor data.
Taylor said: "I don’t know any fundraisers who wouldn’t be shocked if they thought they’ve created anxiety and distress to members of the public. Where that’s happened, I want to apologise for that and say sorry, we have fallen below the expectations of the public."
He also said that the "vast majority" of fundraising was done to a high standard, but admitted that certain unacceptable practices did take place, adding: "Data selling shouldn’t be buried in the small print and I expect that to be dealt with."
The letter - co-ordinated by the IoF, one of three separate bodies with a role in the self-regulation of fundraising in the UK - begins by saying: "We live in an incredibly generous country. For generations, British people have dug deep to support a wide range of great causes here at home and overseas."
It goes on to say: "We know that there have been times where fundraising practice has failed to live up to these high standards. We are determined to change that. No one should ever feel pressured into giving. The vulnerable should always receive the strongest protection. And we need to act quickly and decisively when any fundraising practice is found wanting."
The signatories also welcome the ongoing review of fundraising self-regulation by Sir Stuart Etherington, chief executive of charities membership body the NCVO, and are committed to supporting a strengthened IoF Code of Fundraising Practice.
"The trust put in us by our supporters demands the highest standards of fundraising. We must always strive to meet them," the letter, which can be read in full on the IoF website, concludes.