The voluntary sector is good at what it does but bad at communicating it, according to the NCVO.
The view is expressed in an NCVO report called Accountability and Transparency, which picks up on the key issues that emerged from a fundraising summit the umbrella body held in June.
Charities agreed at the summit that it would be a good idea to produce a generic statement on how they aim to be efficient and effective. They suggested this could be included in their publicity material as one way of changing perceptions about what they do.
The report asks charities to give their feedback on the idea.
"As the voluntary sector has modernised and grown over the past decade, it has often failed to communicate effectively to the media and wider public the nature of its modernisation," said NCVO chief executive Stuart Etherington. "Some of our largest and most successful fundraising organisations have now agreed that it is time to act."
Charles Cox, head of charities at report sponsor PKF accountants and business advisers, said: "This is an important area for debate and we hope that this report will stimulate the sector to engage with it."