The income of the NSPCC fell by £12.9m in the last financial year, its latest accounts show.
The children's charity’s annual report shows its income fell to £135.7m in 2011/12 from £148.6m in 2010/11 - a drop of 8.7 per cent.
The latest figure is £18.9m lower than in 2009/10, when it had an income of £154.6m.
A spokesman for the charity said more than half of the decrease since 2009 was as a direct result of the reduced grants for its helplines from the Department for Education.
"The NSPCC, like most charities, has been weathering a tough economic climate since 2008," he said. "Last year’s total income was lower than the previous year, mainly due to a reduction in overall income from fundraising events and statutory sources."
Income from fundraising events, sales of goods, sponsorship and promotional activity fell by £3.7m to £7.8m. The report said this was because the previous year included some "hugely successful" events that were not repeated. Corporate partnerships have also suffered due to difficult trading conditions, it said.
Funding from local authorities and government fell to £11.1m, down from £17.1m in 2010/11. Voluntary income, including that from monthly donations, fell £2.5m to £114.4m.
Legacy income remained the same as last year at £20.1m. The charity also saw income from community fundraising increase by £700,000 to £8.1m.
The spokesman said that despite the reduction in funds raised, the NSPCC opened 40 new centres in 2011/12 and its services are reaching 30 per cent more children.
Earlier this month, Andrew Flanagan, chief executive of the NSPCC, announced that he would stand down in March for personal reasons.