Membership of the National Council for Voluntary Organisations grew by 7 per cent last year to more than 14,000 organisations, the latest accounts show.
The accounts, which cover the year to 31 March 2019, show that the NCVO had 14,426 members, up from 13,479 the year before.
This means that membership has more than doubled in 10 years, with the NCVO’s 2008/09 membership figures at 6,950.
The accounts also show that 96 per cent of members renewed their memberships in 2018/19.
The NCVO also reported a rise in income last year, from £8.4m in 2017/18 to £8.9m, albeit thanks largely to a grant of £475,000 awarded earlier this year for leading a partnership to create new safeguarding guidance.
Spending also rose, with the accounts showing £8.4m of expenditure, compared with £8.3m the previous year.
In his introduction to the accounts, Peter Kellner, outgoing chair of NCVO, said: "This year marked the final year of our five-year strategy, set out in 2014. We’re pleased that the aims we set then still feel relevant now.
"With our new chief executive, Karl Wilding, starting in September 2019, we are beginning the process of developing a new strategy and expect to complete this in 2020."