The Public Fundraising Regulatory Association will write to its members advising them of cold calling control zones where it thinks they can legitimately carry out door-to-door fundraising.
The PFRA has concluded that some zones have not been set up in accordance with guidance from the Trading Standards Institute and will tell members it thinks they can carry out door-to-door fundraising in such areas.
The PFRA will also give its members a risk-assessment template to use when deciding whether to use the fundraising method in any specific cold calling control zone.
The zones, which are set up by local authorities working with police, trading standards bodies and residents, are areas where signs are displayed saying "no cold calling". The zones have no statutory force.
The Institute of Fundraising has updated its code of practice on face-to-face fundraising to say that it is up to charities to decide whether to send fundraisers into a cold calling control zone, and that it is legitimate to do so if the charity believes the zone has not been set up in line with Trading Standards Institute guidelines.
Mick Aldridge, chief executive of the PFRA, said: "The key thing is that cold calling controls are not legally enforceable, and our job over the coming months will be to give clear guidance to our members on what they can and can't do with regard to these zones."