The Credibility Bureau Accreditation Scale is based off letter ratings.
The scale breaks down as follows:
A – Good standing
B – A few complaints, but generally safe to work with
C – Many unresolved complaints. Ask for references before working with them
D – Do business with extreme caution
E – Not in good standing, has many unresolved complaints
F – Avoid business
Factors involved in rating
How Long the Business Has Been Operating
Positive Reviews
Consumer Transparency
Customer Satisfaction
Responsiveness/Customer Service
Years without a complaint
Misleading Advertisements
Number of complaints
Number of Resolved Complaints
Number of Unresolved complaints
Size of the Company
Type of Business