The Fundraising Regulator must avoid treating all charities in the same way if it hopes to persuade more of them to pay its levy, according to Vicky Browning, chief executive of the charity leaders body Acevo.
In a statement made after the Fundraising Regulator published a list showing the names of the 162 charities that have not paid the levy to contribute towards its costs, Browning warned that the regulator needed to do more to tailor its arguments to different types of charities.
She said the list published by the regulator showed that certain kinds of charities were more likely than others not to pay, primarily religious or medical charities and those in the arts.
"This demonstrates a need for the Fundraising Regulator to engage with representatives from these types of charities and understand what their concerns are," Browning said.
"The sector is not homogeneous: the same argument isn't going to work with everyone. Charities that have concerns about paying need to see and hear that their perspective is understood and being taken into account."
Browning said it was up to each charity to make up its mind on whether or not to pay the levy, but Acevo’s view was that it was better to have the voluntary self-regulation offered by the Fundraising Regulator than to have government legislation imposed on the sector.
The regulator’s list included 1,570 charities, the majority of which had paid the levy, but showing the names of 162 that had not. The regulator said another 95 charities not included on the list were currently negotiating with it about making the payment.
Of the 162 that have not paid, 13 have agreed to pay the levy next year, but not this year.
At least 85 of the 162 have charitable objects relating to medicine, religion or the arts, including museums.
Browning said: "Charities not paying the levy on the principle that donors’ money was not intended for the Fundraising Regulator must measure the risk against the principle and consider whether the principle should itself be subsidised by the majority of the rest of the sector that is paying the levy."
A spokeswoman for the regulator said it engaged with all charities that got in touch to express concerns about the levy, but if charities did not reply to emails and letters it was "near impossible" to discover exactly what their concerns were.
"Where charities have refused to pay, we will continue to engage with them individually, and it is helpful that some have said they will start to pay the levy in year two," she said.
The regulator was always happy to discuss any issues, she added.
"Many arts, faith and medical research charities have paid the levy, and we are pleased that they support independent regulation," she said.
"As Acevo points out, the sector is not homogeneous, so it can be difficult to do this where charities are not part of wider networks."