Charities will be asked this week to give their opinion on whether will writers should be regulated.
Steve Brooker, manager of the panel, told Third Sector that anyone was permitted to set up a will-writing business. Wills could sometimes be declared invalid if there were technical errors, he said - and if this happened, the assets were distributed under laws written in 1925, which could result in only blood relatives being allowed to receive anything.
But Brooker said that unnecessary regulation of will writing might also present problems for charities.
"Charities may also be involved in providing will-writing services, and regulation could affect their ability to do this," he said. "It might increase the cost of wills and dissuade consumers from writing them in the first place, meaning less legacy income."
Iain McAndrew, vice-chair of Remember A Charity and head of legacies at Save the Children, said such regulations were important because they gave consumers confidence that their wishes would be taken into consideration.
Chris Millward, legacy promotions manager at Macmillan Cancer Support, said: "We would be supportive of more regulation being put in place for will writers, providing the same level of safeguards as seen with solicitors registered with the Law Society."
Charities can give their views by visiting www.legalservicesconsumerpanel.org.uk from 22 September.