Taxation and tax law cannot exist without biases because tax law can be seen per definition as a set of biases. Even if the state pursuing its fiscal policy cannot be neutral, one can expect to enforce the principle of equal treatment before the law. Besides, state intervention need be in proportion to the objectives of the policy of redistribution or economic stabilization. Also, fiscal policy need rely on a system of tax administration that operates in accordance with the principles of openness, good governance and legal certainty. It is ideal if the legal regulation of the procedure of tax administration is fully fledged. The legal regulation of the tax liability need be comprehensive and cover all the processes of gathering tax information, identifying the tax liability and collection of taxes. Moreover, tax administration and administrative law are inadvertently in a need of being completed by private law. Where tax authorities are not explicitly authorised by statutory law to act, they must rely on the principles that are in accordance with the constitutional order. Notably, in Hungary, there is no statutory law that would preclude the universal effect of the Civil Code, covering all the financial relations whether to be made between private persons or between private persons and the representative of the public. Finally, for the purposes of approximating an ideal tax system, the possibility of horizontal coordination must not be left out of consideration. In this context, legal and tax planning and the choice of legal and tax regimes by parties have come to the forefront. Bargaining (e.g., advance ruling) has not been strange from tax law either.