East Sussex County Council's Trading Standards Service has been running its approved trader Buy With Confidence scheme since May 2004.
Nearly 280 East Sussex businesses have signed up to the scheme.
Buy With Confidence is designed to support honest traders and help to protect people from being ripped off by rogue traders.
Now the county council plans to increase awareness about the scheme with an advertising campaign that will include bus and local radio advertising across the county. The council hopes the campaign will lead to more businesses signing up to the scheme and more people choosing to buy goods or services from the official list of approved traders.
County council chairman Cllr Bob Lacey was due to launch the advertising campaign on yesterday.
A new Buy With Confidence directory, listing approved traders across the county, is now available free of charge from Trading Standards by telephoning (01323) 418201 (option two). The directory can also be picked up in county libraries.
Councillor Bob Tidy, county cabinet lead member for community services, said: "The Buy With Confidence scheme is a real win-win.
"It supports honest and reliable businesses and helps to promote their goods and services to the public and it also helps to protect residents from being ripped off by cowboy traders. The scheme has proved a great success and I am sure that the new advertising and awareness campaign will help to take it a stage further."