A certifying letter signed by an official from the company an applicant is using for MDRT qualification is required when applying under the commission or premium method. Otherwise, the application will be considered incomplete and membership may be denied. These companies may include life insurance companies, agencies, brokerage companies, broker/dealers, banks or mutual fund companies. Also acceptable would be a certifying letter completed by a representative of the company/broker dealer/brokerage agency, a Certified Public Accountant (or equivalent), or a representative of the applicant's personal agency/corporation or office.

A Certified Public Accountant (CPA) or the equivalent may sign certifying letters for financial planning fees/fees for advice that are paid directly to the producer when applying under the commission or premium method.

Brokerage companies are defined as third party wholesalers of insurance and investment products that are provided to agents on behalf of insurance and investment companies. Should an applicant be an official of a brokerage company, the product provider who pays the commissions must sign the certifying letter.