The Legal Services Board (LSB) is recommending that will-writing be subject to regulation after completing a two-year investigation during which it said it uncovered a "compelling case" for regulatory oversight of the industry.
The LSB has submitted a report to Lord Chancellor Chris Grayling recommending he amend the list of reserved activities to include will-writing.
However, it has not recommended Grayling do the same for estate administration activities.
Grayling has 90 days to make a decision.
Currently, will-writing activity is not regulated, though many service providers - such as solicitors, who are regulated for their other activities - offer it. Solicitors, the LSB noted, turn over more than £1bn annually conducting will-writing work.
The LSB said that a two-year investigation had uncovered "consistent and compelling" evidence that many consumers are receiving a poor service from will-writers, resulting in financial loss and "emotional harm".
Its probe included a shadow shopping exercise which it said provided "strong evidence" that many wills are unlikely to achieve what the testator wants.
A particular problem with unregulated providers of will-writing activities is instances of lost wills, exacerbated by the fact that 60% of independent will-writing firms close within their first four years of operation, it added.
The LSB said its recommendations, if approved, would give consumers better protection and a stronger chance at redress by allowing access to the Legal Ombudsman.
They would also create a level-playing field between traditional law firms and new forms of service provider, making both subject to equivalent regulation.
LSB chairman, David Edmonds, said: "[We believe] new regulation is a proportionate response in the light of a compelling case underpinned by appropriate evidence.
"We are confident that the evidence base for our proposal to add to the existing list of reserved legal activities is compelling. It is, of course, for the Lord Chancellor to decide whether to take this forward."
The LSB is also proposing that probate activities, which are presently listed activities, remain so.
The proposals, if approved, could mean that any will-writing financial advisers would have to apply for will-writing authorisation from another regulator, should the Financial Conduct Authority not request the right to grant that power.
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