Like laboratories, certifiers may also participate in an accreditation program as an outside check of their internal quality control program, as proof of competence to higher level management within the organization, as a competitive advantage over other unaccredited programs, as a means of protection in liability proceedings, or as a means of establishing credibility with the public.

The reasons for and benefits of seeking accreditation are many. In general, however, certifiers (and laboratories) participate in accreditation programs in expectation of some type of economic return on the resources they invest in obtaining the accreditation, such as new or expanded business opportunities. Again like laboratory accreditation programs, not all certifier accreditation programs are equally thorough and not all accrediting bodies are equally competent. Some factors that can be used to evaluate a certification program accreditation process were previously discussed under laboratory accreditation. These factors affect the ability of the certification program accreditation process to provide assurance that an accredited certifier is capable of competently conducting certain certification procedures for one or more products as defined in the scope of the accreditation.

The U.S. certification program accreditation system is less complex than that for laboratory accreditation, primarily because the U.S. has significantly fewer programs for accrediting certifiers than for accrediting laboratories. The two most prominent programs are the ones run by OSHA (which was mentioned above) and by ANSI.

OSHA's program covers electrical equipment/materials used in the work place. All electrical products used in the work place must be tested and listed or labeled by a certifier (known as a Nationally Recognized Testing Laboratory or NRTL), which is recognized/approved by OSHA. Participation in the OSHA program is voluntary for certifiers; however, if they wish to test such products, they must be recognized/approved by OSHA.

ANSI also conducts an accreditation program for certifiers, which was established in the 1970s. ANSI's policies and procedures were revised in 1992 to be consistent with both relevant international standards and guides and with anticipated obligations under the WTO Agreement. ANSI accredits certifiers in a number of areas ranging from construction materials to drinking water additives to gas and electrical appliances and accessories.