Charities are being asked to sign a transparency manifesto that was launched on Friday.
The manifesto, published by the Impact Coalition, aims to improve levels of accountability and transparency in the voluntary sector.
Charities that sign agree to follow a set of principles that commit them to being open and honest about their operations.
"Recent events in the media have shown us that we still have a long way to go on that front," said Stephen Bubb, chief executive of Acevo, the membership body for charity leaders that funds the coalition.
"We cannot afford to continue to be complacent about the high levels of trust the public stores in us. That trust is fragile and we have a duty to demonstrate why we deserve it.
"We want the manifesto to become the benchmark by which all charities measure their progress."
The manifesto was drawn up by the steering group of the coalition, which was formed in 2005 and now consists of 380 charities and trade bodies.