The subject of consideration in the publication is associated with a set of problems related to the implementation of the principles of good faith in budget law. The range of issues arising during adaptation to the budget sphere and application within its framework of the principles of good faith, received from state laws, is analyzed, important aspects and potential risks of the said implementation are identified. In the final study, conceptual answers to the questions posed are formulated, recommendations, target provisions for ensuring the principle of good faith in the sphere of budget law are formulated.