A Business Administrator is typically an owner, officer, member, partner, trustee, receiver or authorized representative for a business. The Business Administrator is the only one who can grant or delete access to the business’ MyTax Missouri account.  To register as a Business Administrator, you must provide your First and Last Name, Social Security Number, Date of Birth, Phone Number and E-mail Address.  To be authorized on a business, you will need the Business’s Legal Name, Missouri Tax Identification Number, Business PIN number, and Federal Identification Number, if applicable.