Town spent £790,210 on agents’ fees between February 1st 2018 and January 31st this year.
Of the other clubs in the Championship, only Wigan, Bolton, Blackburn, Millwall and Rotherham spent less on what are now officially known as intermediaries.
The ÂŁ790,210 covers 20 transactions, the signings, both permanent additions and loans, made by Paul Hurst last summer and Paul Lambert in January, as well as new contracts for players already at the club, and also the exit of Tommy Smith to the Colorado Rapids in February last year.
The figure is significantly up on the Blues' spending in the previous year when only ÂŁ241,969 was paid out to intermediaries. A year prior to that Town spent ÂŁ303,978.
The FA has been required to publish clubs' spending on intermediaries by FIFA regulations since April 2015.