Tax Controversy is defined as any activity against a taxpayer being undertaken by the Criminal Investigation Division of the Internal Revenue Service or any activity being undertaken by any other part of the Internal Revenue Service to which the taxpayer does not agree. Because the various laws within the Internal Revenue Code are extremely complex, knowledgeable representation is necessary to defend someone against any actions by the Internal Revenue Service.

Various state departments of revenue usually depend on actions taken by the Internal Revenue Service. These state revenue departments then send a bill based on their percentage of taxation since the Internal Revenue Service has already litigated the issue. On rare occasions the state departments of revenue take their own action. These actions then depend upon the laws of that state and have to be litigated according to those laws. There again knowledgeable legal representation is always needed.