High Quality Content by WIKIPEDIA articles! Digital Federal Credit Union (DCU) is a credit union based in Marlborough, Massachusetts. It has over 350,000 members and is among the top 25 credit unions in the U.S.A. and the largest credit union head quartered in New England as measured by assets. DCU has in excess of $3.65 Billion USD in assets. DCU is regulated under the authority of the National Credit Union Administration (NCUA) of the US federal government.