The number of donors using payroll giving fell by 4 per cent in the most recent tax year, but the amount they gave rose, according to figures released last week by HM Revenue & Customs.
The total number of payroll givers in 2009/10 dropped to 724,000, compared with 754,000 the previous year and 758,000 the year before that.
Despite the drop in donor numbers, the amount of money raised through payroll giving rose to £106m, up on the previous year's figure of £104m but down on 2007/08, when donors gave £109m.
Peter O'Hara, managing director of payroll giving agency Workplace Giving, said the drop in the number of donors was largely down to the "raft of redundancies" that had hit the UK.
"The interesting factor is that donations are still going up," he said. "Our average donation has gone up by £1.50 a month in the past year as people still in jobs become more generous."
Panikos Efthimiou, charities training manager at the Charities Aid Foundation, said he thought donations had risen despite numbers falling because of increasing take-up of payroll giving by higher-rate taxpayers.
"For 40 per cent and particularly 50 per cent taxpayers, this is the most effective way to give, and wealthier donors are waking up to that," he said.
"One thing we do at CAF is to encourage charities to engage with their donors and encourage those who pay higher-rate tax to give through payroll giving."
£3.11bn The total value of tax reliefs for charities in the tax year 2009/10, according to provisional figures from HM Revenue & Customs. This was made up of tax relief for charities of £2.4bn and tax relief for donors of £710m.
£1.01bn The value of Gift Aid payments to charities, compared with £946m the previous year.
£310m Tax relief paid to higher-rate taxpayers. Individual donors also received £300m relief on inheritance tax, £70m on gifts of shares and about £30m on payroll giving.
68,100 The number of Gift Aid repayments received by charities. About 29,100 claims were for less than £1,000, and 110 were for more than £1m.