Unicef UK's income has dipped below £100m for the first time since 2014, according to its latest annual accounts.
The accounts, filed with Companies House on Friday, reveal that revenue at the children's charity's declined by 0.8 per cent, from £100.2m in 2017 to £99.4m last year.
Income from donations and legacies fell from £92.4m to £89.5m, mainly due to downturns in revenue from direct marketing and trusts and foundations.
For the third year running, spending exceeded income. But the £100.3m figure for expenditure was down on the £102.9m of the previous year.
The number of fundraising staff fell from 154 to 123, although the total number of employees declined only slightly, from 355 to 350.
Asked why the number of fundraising staff had fallen, a spokeswoman for the charity said: "Our structure reflects our ambition to have the most positive impact we can for children around the world by ensuring we are staffed in the most appropriate areas.
"The number of staff we employ or replace after they move to new roles varies in line with current projects and priorities."
Spending on salaries and wages, however, rose slightly, from £12.2m to £12.3m.
Four staff received gross pay and pension contributions of more than £100,000.
Michael Penrose, executive director of the charity, received gross pay and pension contributions totalling £135,000, compared with £120,000 the previous year.
Asked about the pay rise, the spokeswoman said: "We review benchmarking data on a regular basis to ensure we remunerate in accordance with best practice across the industry.
"Charities such as Unicef UK are complex organisations with the same needs for professionalism and effective management structures as similar organisations in the private sector.
"Charities need to pay salaries that are sufficiently competitive to attract and retain the right chief executive with the right skills and experience to deliver the most money and the greatest positive impact for the world’s children."
Unicef UK incurred redundancy costs of £204,000, up from £92,000 in the previous year, the accounts reveal.
Justin Forsyth, deputy executive director of Unicef, resigned in February after he apologised for sending inappropriate texts to junior staff during his time as chief executive of Save the Children UK.
But he was employed by the global arm of Unicef, not the UK charity, so he does not feature in these accounts.