The article is focused on studying the possibility to modify and terminate legal services supply agreement. The author has noted that the volume of foreign investments is a significant stimulus for the recovery of the domestic economy, and this should be facilitated by proper protection of the rights of investors as less protected participants of investment relationships. All this will contribute to the need to streamline legislative mechanisms for regulating relations in the sphere of services provision. In particular, civil regulation of legal services, despite the extraordinary social importance played by relations on providing legal services in society, has not been sufficiently developed yet, in order to affirm that a fairly well-balanced regime for regulating these relations functions in Ukraine. The author of the article has indicated that the right to apply measures of operational influence by legal services’ customers requires a clear description in the legislation, but not to be established through a multi-stage interpretation of the relevant norms. The exercise of such a right should not depend on its enshrining in the terms of legal services supply agreements, i.e. its normative basis should be the relevant legal norms, which should increase the guarantee of protection of the rights and interests of the customers of such services as less protected participants of contractual relations. The author has proved that the application of legal services on protection by the customers in the form of terminating the agreement, first of all by filing the corresponding claim to the court, has no particular specificity, compared to similar protection within other contractual obligations. The analysis of court practice indicates the lack of acute problems requiring scientific description and resolution in this regard. There is a stable court practice in Ukraine regarding the protection of legal services’ customers through the termination of relevant agreements. Termination of the contract, as a terminating legal fact, protects rather the customer’s interests, but not the rights (for safeguard of assets; for concluding the same meritous contracts with other entities, etc.). The author of the work has specified that modification and termination of legal services supply agreements, which are carried out based on the understandings between the parties, as a general rule, are not applied in the context of the parties’ reaction to the offense committed by the counterparty, but due to other motives. In particular, a significant modification of circumstances can be mentioned among such motives.