The COIF Charities Deposit Fund, the cash deposit account run by investment managers CCLA, has reached the landmark of £1bn of investments.
The pooled fund, registered as a charity with the Charity Commission, has 13,700 clients and more than 17,000 accounts. It is intended to accrue interest for charities' short-term reserves.
At a reception at CCLA's London offices, managing director Andrew Gibbs said: "This is a significant achievement in terms of total deposits and the fund's longevity and also a tribute to the thousands of charitable investors who continue to choose the fund as a safe and competitive home for their short-term deposits."
During the fund's 20-year existence the interest rate has swung from a high of 15.09 per cent in 1989 to a low of 3.15 per cent in 2003. The current deposit rate is 4.55 per cent.
CCLA is believed to be the UK's biggest fund manager of charity investments.
The organisation manages more than £5.2bn of charitable funds.