The study focuses on the issues of using foreign powers of attorney to dispose of immovable property located in in Ukraine. The unprecedented scale of migration of the Ukrainian population to European countries caused by the full-scale invasion of Ukraine by the Russian Federation continues to provoke legal issues that require research and answers. Among them is the issue of disposal of immovable property located in Ukraine on the basis of foreign powers of attorney.

The article addresses the following issues: the law of which country such a power of attorney must comply with; whether it must be created in the form of an authentic instrument; and whether certification of the authenticity of the signature on such a power of attorney is sufficient. As one of the possible examples, the article considers the situation of a power of attorney issued by a Polish notary for disposal of immovable property located in Ukraine. It is concluded that such a power of attorney must be authenticated, i.e., drawn up in the form of a ‘notarial act’ under Polish law, which is equivalent to a notarial authentication under Ukrainian law.

The article pays special attention to the concept of an ‘authentic instrument,’ which is analogous in its characteristics to a document authenticated by a notary under Ukrainian law. An authentic instrument is a document issued by a public authority; this authenticity should relate to the content of the instrument and not only, for example, the signature; the instrument has to be enforceable in itself in the state in which it originates.

The study draws attention to the fact that the law to which a foreign power of attorney must comply depends the interpretation of the provisions of the Law of Ukraine ‘On Private International Law.’ Depending on the strategy interpretation of these provisions, a power of attorney from a country where the concept of an authentic instrument is not used (Sweden, Ireland, Denmark, Cyprus, Finland) may be either recognised or not recognised in Ukraine as legally sufficient ground to dispose someone’s immovable property.

Attention is also paid to the legal consequences of using a foreign power of attorney, which, in accordance with the provisions of a bilateral international agreement between Ukraine and a third country, must comply with the law of Ukraine, but is not authenticated. Such a power of attorney is void pursuant to Article 219 of the Civil Code of Ukraine, but its voidance does not directly result in the invalidity or nullity of the agreement concluded on the basis of the void power of attorney.