Lord Michael Grade, chair of the Fundraising Regulator, has reiterated calls for large fundraising charities to pay the fundraising levy and said it was "unacceptable and unprofessional" that 138 had ignored letters requesting payment.
In a blog on the Fundraising Regulator’s website about his first meeting with Amanda Bringans, chair of the Institute of Fundraising, Grade said more than 1,400 charities had paid or promised to pay the levy to fund the regulator.
"Those charities that haven’t paid are effectively being subsidised by those who have, which is hardly a fair situation," said Grade.
"All of these charities have the ability to pay the levy. It is unacceptable and unprofessional that 138 charities have still not even responded to our several communications about the levy. If a charity feels that it should not pay the levy, we need to know why."
Almost 1,800 charities that spend more than £100,000 a year on fundraising are eligible to pay the levy.
The regulator is due to announce by the end of the month the names of all the charities that fall within the scope of the levy and whether or not they have paid.
Bringans wrote in a blog post about their meeting last month that Grade had agreed to speak more positively about fundraisers after he was criticised by sector umbrella bodies for saying too many charities were "proving to be laggards" in terms of reforming their fundraising practices.
In his post published yesterday, Grade said that some of his words about the sector "have been emphasised by the media", which had focused on his "criticism of the few".
He said: "Yes, we have been firm and will continue to be firm in calling out bad practice.
"However, we have also consistently acknowledged the outstanding work undertaken by charities and fundraisers. Sadly, we don’t have the power to write our own headlines but, whenever the opportunity arises, we will speak positively about the charitable sector and its excellent work."
Grade said in his blog that most larger and many smaller charities were redefining their relationships with donors so the changes so the changes in regulation were an opportunity rather than a threat.
"There are many in business who could learn from this," he said.
"This reflects how fundraisers have been committed to operating to an increasingly high standard.
"It is clear that the public is appreciative when fundraisers interact in a sensitive, considerate manner, understanding the precious trust the public holds in charities and how vital that trust is to ensuring that charities continue to be supported."