Sellers/servicers must be approved to do business with Fannie Mae. Fannie Mae determines a seller/servicer’s qualifications by reviewing the seller/servicer’s financial condition, organization, staffing, selling and servicing experience, and other relevant factors.
See Fannie Mae's website for more information on the application process for approval to do business with Fannie Mae, including:
minimum business requirements,
application review fee, and
any special approvals needed to sell or servicer mortgages with unique requirements.