Charity governance is under-resourced, haphazard and badly managed, according to a report published this week by think tank New Philanthropy Capital.
Board Matters says the largest 20 fundraising charities spend only 0.6p in every pound on governance. The figure for smaller organisations is believed to be even lower.
"In times of economic crisis, muddling along with the public's money is no longer an option," said Belinda Vernon, co-author of the report.
Based on interviews with 50 senior voluntary sector figures and existing data, the report says nearly half of charities have board vacancies and nearly half of the country's estimated 820,000 trustees are aged 60 or more.
It calls for better trustee inductions and evaluations but says paying trustees would "create many new problems", such as conflicts of interest.
"To allow haphazard governance is potentially very damaging, especially in these difficult times," said co-author Eleanor Stringer.
Gill Edelman, former chair of the Governance Hub, said: "There is not sufficient consistent effort to deliver and demonstrate high standards of governance."