Tax Advisor (or Tax Adviser) is a natural person authorized to carry out tax advice, i.e. provide legal assistance and economic and financial advice in taxes, fees and other similar payments, as well as in matters directly related to taxes (e.g. accounting, etc.).
Good knowledge of accounting, tax laws, commercial and criminal law in areas directly related to taxes is a commonplace of Tax Advisors. Due to this complexity of the system, tax advisors usually specialize in a specific market segment.