The research, which was carried out by The Read Group, found that suppression in the industry had increased, with more than 60% of direct mail is being checked against The Bereavement Register, and 55% against the "gone away" suppression file.
Despite the improvements, which The Read Group claim have saved the industry around £77m, the charity sector "languished" behind others -- with 89% of all mailings not screened against gone away file. This equated to more than 380m mailers and £11.5m of waste.
The charity sector was the only area to undergo a decline in suppression usage, dropping from 13% to 11.5% between 2006 and 2007.
The Read Group also criticised the charity sector for "paying little heed" to suppressing deceased data, with only 9% of outgoing direct mail screened against The Bereavement Register compared with an industry average of 60.4%.
The Read Group said the results equated to 76% of UK direct mail being matched against its suppression technology, while the combined use of The Bereavement Register and the gone away suppression file had prevented 145m items of direct mail being sent.
Mark Roy, chief executive of The Read Group, said: "It is encouraging that the use of suppression is significantly up over the previous year. This is almost certainly due to environmental pressure as well as demands for increased efficiency in a tightening market.
"However, there is still further to go. Our research shows that many companies are still failing to suppress and wasting more than £50m a year."