Crimestoppers is planning a donor recruitment and development drive for autumn and the new year.
The charity, which is best known for its anonymous phone line for reporting information on crime, will begin by sending out mailings aimed at increasing the value of existing donors.
Crimestoppers spokeswoman Tara Snowden said: "We want more people to know about our service. That is why we need more donors and a higher profile. We regard this as a long-term project."
The charity has appointed LWC Direct Marketing and Gilliland Direct Marketing to jointly handle the campaign.
Crimestoppers has received more than 640,000 calls resulting in 57,000 arrests since it launched in 1988.