Non-contractual obligations in Ukrainian civil law doctrine are traditionally described through separate legal institutions: compensation for damage, unjust enrichment, management of another’s affairs without mandate, rescue and other special constructions. This approach is necessary for analysing the relevant legal facts, the conditions under which obligations arise and the available remedies. However, it does not fully explain the systemic place of non-contractual obligations in private law or the criteria for their coordination with contract, property-law remedies, the consequences of invalid transactions and other private-law regimes. The purpose of this article is to develop and justify a doctrinal model of non-contractual obligations as a coordination mechanism of the private law system, to define its key categories and to formulate criteria for the delimitation, concurrence and interaction of non-contractual claims with other private-law remedies. The article proposes to use the category of private-law imbalance as a general concept covering patrimonial loss, unjustified patrimonial gain, unauthorised intervention in another’s sphere, the creation of a risk of harm, costs incurred to avert it and other disturbances of the equilibrium between subjects of private law. It is argued that compensatory, restitutionary, intervention-based and preventive-special obligations form an autonomous but not isolated functional subsystem of private law. The article concludes that the coordination of non-contractual obligations should be based on the principle of functional complementarity. This principle preserves the autonomy of each private-law regime within its proper sphere of regulation, while allowing their interaction where one factual situation gives rise to several legally relevant dimensions. The proposed model is relevant for determining the limits of civil liability and damages in cases of concurrence of claims and for the recodification of Ukrainian civil legislation, as it helps avoid chaotic concurrence of claims, double recovery and mechanical layering of legal rules.

Authored books

1. Baloch T A, Unjust Enrichment and Contract (Hart Publishing 2009).

2. Dannemann G, The German Law of Unjustified Enrichment and Restitution: A Comparative Introduction (Oxford University Press 2009) https://doi.org/10.1093/acprof:o so/9780199533114.001.0001.

3. Farnsworth W, Restitution: Civil Liability for Unjust Enrichment (University of Chicago Press 2014) https://doi.org/10.7208/chicago/9780226144337.001.0001.

4. Gordley J, Foundations of Private Law: Property, Tort, Contract, Unjust Enrichment (Oxford University Press 2006) https://doi.org/10.1093/oso/9780199291670.001.0001.

5. Grundmann S, Micklitz H-W, Renner M, New Private Law Theory: A Pluralist Approach (Cambridge University Press 2021) https://doi.org/10.1017/9781108760089.

6. Markesinis B S, Unberath H, The German Law of Torts: A Comparative Treatise (4th edn, Hart Publishing 2002).

7. Terrp F, Simler P, Lequette Y and Chpnedp F, Droit civil. Les obligations (12e pd, Dalloz 2019).

8. Vicente D M, Comparative Law of Obligations (Edward Elgar Publishing 2021) https://doi. org/10.4337/9781789905816.

9. Virgo G, The Principles of the Law of Restitution (3rd edn, Oxford University Press 2015) https://doi.org/10.1093/acprof:oso/9780198726388.001.0001. Edited books

10. Cartwright J, Whittaker S (eds), The Code Napoléon Rewritten: French Contract Law after the 2016 Reforms (Hart Publishing 2017).

11. Van Erp S, Akkermans B (eds), Cases, Materials and Text on National, Supranational and International Property Law (Hart Publishing 2012).

12. von Bar Christian, Clive Eric, Schulte-N|lke Hans, (eds), Principles, Definitions and Model Rules of European Private Law: Draft Common Frame of Reference (DCFR) (Full Edition, Sellier European Law Publishers 2009) Introduction, paras 34–40; Books V–VII. 149 ПРАВО УКРАЇНИ • 2026 • № 2 • 134-149 НЕДОГОВІРНІ ЗОБОВ’ЯЗАННЯ ЯК КООРДИНАЦІЙНИЙ МЕХАНІЗМ СИСТЕМИ ПРИВАТНОГО ПРАВА

13. Spasybo-Fatieieva I (ed), Traktat pro kompensatsiiu v pravi (ECUS 2026) (in Ukrainian).

14. Spasybo-Fatieieva I (ed), Vchennia pro tsyvilno-pravovu vidpovidalnist (ECUS 2025) (in Ukrainian).