A financial expert with advanced training and knowledge of tax law. The services of a tax advisor are usually retained in order to minimize taxation while remaining compliant with the law in complicated financial situations. Tax advisors can include Certified Public Accounts, tax attorneys and financial advisors.

Tax advisors and preparers are regulated but not licensed by the Internal Revenue Service. Treasury Department Circular No. 230. Reg. 10.33(a) of the circular outlines the duties of tax advisors. There can be penalties and disciplinary action for failing to follow the standards outlined by the IRS.