Aid charity International Medical Corps (UK) spent just $43,000 (£34,000) on fundraising staff in the year to June 2017, but brought in $15.8m (£12.5m) in donations and $156.8m (£123.8m) overall.
The figures are revealed in the Fundraising Directors Survey, published next month in Fundraising Magazine, which shows that the charity is now the 91st largest fundraiser in the UK.
Donated supplies make up the majority of its fundraised income.
The charity has more than doubled its income since 2013. As a result it is rising fast in the the haysmacintyre / Charity Finance 100 Index, the list of the largest charities in the UK, which is based on the average income reported in charities' last three sets of annual accounts.
Last year IMC UK was in 61st place, and it is expected to rise again when the next index is published in April.
The charity works in 26 countries, and employs a total of 4,196 staff, making it into one of the biggest international aid organisations registered in the UK.
The charity’s income is almost entirely restricted. As a result, despite its rapid growth, it has a relatively low level of free reserves – just $148,000 (£116,890) in the most recent accounts.
Editor's note: This story has been updated to clarify that the majority of the fundraised income is in the form of donated supplies