The ifs School of Finance accounts show a £1.4m deficit last year, following a surplus of £1.7m in 2007.
Its annual report and accounts for 2008 shows the ifs, which is a registered charity, saw expenditure reach £16.5m in 2008 while its total income was £15.1m.
It has seen little income growth since 2004 when it took £15.5m. Income increased to £17.4m in 2007 but fell back to £15.1m last year.
The ifs says charities cannot accumulate funds unless it is for a particular reason.
A spokeswoman says the body has a strong balance sheet and is investing in building the organisation. She says: “The deficit in 2008 is due to significant investment in new premises – our new student campus in the City.”
Evolve Financial Planning director Jason Witcombe says: “As advisers, we treat suppliers of exams as any other supplier and have to make sure they are on an even financial footing.
“If the reasons for the 2008 deficit are easily explained, as they seem to be, then that is fine, but it is not something advisers would want to see continuing for any length of time.”