You don’t have to look far to find some very impressive statistics about the size and scope of the charity sector in the UK.
Some 200,000 charities employ about 880,000 people, turning over an estimated £48bn each year, according to the research charity nfpSynergy.
These huge and impressive numbers are clear evidence of a dynamic sector powered by the generosity of the public.
And make no mistake, our sector is making a real difference to lives nationally and internationally.
From Barnsley to Bangladesh, British charities, big and small, are raising awareness, funding research and responding to crisis.
The difference charities can and do make has become all the more important in recent years against a backdrop of domestic austerity and global turbulence.
This vital work risks being undermined, however, by an accountability puzzle that affects charities of all sizes.
That puzzle currently presents a series of challenging problems: to whom are charities really accountable and how do they demonstrate that accountability?
This goes beyond being regulated: it speaks to the very identity of organisations in which and with which we work. If we have to rethink our accountability, as entities and as a sector, we need to rethink what we are really accountable for, and how we turn the altruism of our donors, supporters and volunteers into maximum impact on people's lives.
As a sector we have to start to put in place mechanisms that not only communicate, but also convince donors, supporters, beneficiaries and the public more widely of the value of the sector’s activities, the impact that we have individually and collectively.
In short, we can’t just assume that the third sector mysteriously produces good deeds. We need to be able to spell it out in tangible, persuasive terms.
We must set out an agenda for change that governs the sector as a whole.
This means shared values, standards, best practice and approaches to impact.
We must demand of ourselves what we demand of others and expect to be judged by the standards of others, rather than ourselves as a sector.
It will be a task for the sector bodies to get together and deliver this agenda in a way that inspires and motivates to transformation, rather than looking to agreement at the lowest common denominator.
We should ask ourselves tough questions about whether a particular charity is actually the best way of addressing an issue.
We should also applaud those who embrace collaboration, joint working and mergers so that charities deliver more, ideally, for less.
Issues of accountability and transparency have been at the heart of some the greatest challenges to the third sector in recent times.
Poor fundraising techniques, inappropriate data use and inadequate safeguarding have all meant that public perception of the charity sector has been badly damaged over the past five years.
If we are to do justice to the good work of our sector and continue to deliver in increasingly challenging and unpredictable times, we must work together and take decisive action.
Simon Gillespie is chief executive of the British Heart Foundation. He will retire at the end of the year