The consultation follows last week's meeting on the subject of a coalition of sector umbrella groups, fundraising professionals and eight interested charities. Treasury and Home Office officials were also present.
Charities will be asked whether and how they might benefit from US-style lifetime legacies, which would allow people to give assets or shares to a charity but keep any income derived from them during their lifetime.
Andrew Watt, deputy chief executive of the Institute of Fundraising, said he hoped the response would come in time to convince the Treasury to include the proposal in its pre-Budget statement in November.
"The Treasury has changed its structures so it can think outside the box on charities, and we have a great opportunity to work with them," he said. "If we don't get an announcement later in the year, we might have missed the boat."
The consultation will include members of the institute, the Charity Tax Reform Group and the Institute for Philanthropy, which organised last week's meeting.
One question was whether lifetime legacies would mainly benefit the arts and education, as is the case in the US. But Watt said he thought all kinds of charities would benefit.