A mortgage servicer is a company to which some borrowers pay their mortgage loan payments and which performs other services in connection with mortgages and mortgage-backed securities.
The mortgage servicer may be the entity that originated the mortgage, or it may have purchased the mortgage servicing rights from the original mortgage lender.
The duties of a mortgage servicer vary, but typically include the acceptance and recording of mortgage payments; calculating variable interest rates on adjustable rate loans; payment of taxes and insurance from borrower escrow accounts; negotiations of workouts and modifications of mortgage upon default; and conducting or supervising the foreclosure process when necessary.
Many borrowers confuse their mortgage servicer with their lender. A mortgage servicer may be a borrower’s lender, but often the beneficial rights to the payment of principal and interest on mortgages are sold to investors such as Fannie Mae, Freddie Mac, Ginnie Mae, FHA, and private investors in mortgage securitization transactions.
Banking organizations often perform mortgage servicing not only for mortgages they originate but for others where they have purchased the servicing rights.
Source : Wiki