How the court reads an expert opinion on foreign law, why some opinions work and others do not, and what an opinion must contain for the court to be able to rely on it.
The testator lived in Monaco but wrote his will in Russian. The text left the estate to a "fund" - a word that may equally denote a legal entity to be set up or simply a pool of assets. Foreign experts offered several possible French renderings of it, and the choice between them determined who would receive the estate: a newly created legal entity, or the claimants directly.
The court relied on a note from a French professor and an opinion from a Monaco advocate, and decided the case. The Supreme Court of the Russian Federation set the decision aside and described what the first-instance court had done in words worth remembering by anyone commissioning an opinion on foreign law:
"the first-instance court, faced with a question of law, effectively abstained from taking the measures necessary to ascertain the content of the rules of foreign law"
Ruling of the Supreme Court of the Russian Federation of 30 January 2024, No. 5-KG23-139-K2 (unofficial translation)
The Supreme Court criticised the fact that the first-instance court had confined itself to the construction of a single article of the Monaco Civil Code, instead of examining the law applicable to the succession relationship as a whole.
Below are three cases in which opinions on foreign law played very different roles. In the first, the opinion did not help. In the second, the courts rejected it and the Supreme Court disagreed. In the third, it worked. Together, the three cases show what a court expects from such a document.
In brief
Foreign law applies where the terms of the transaction or conflict-of-laws rules point to it. The mere presence of a foreign party to a dispute changes nothing in itself.
It is the court that establishes the content of foreign law. The parties are entitled to assist it with sources and opinions - and, in commercial disputes, are required to do so where the court has so ordered.
An opinion answers questions of law: the rules, their official construction, and how they are applied in practice. The assessment of evidence and findings of fact remain with the court.
Case one
A will, Monaco and the word "fund"
Ruling of the Supreme Court of the Russian Federation of 30 January 2024, No. 5-KG23-139-K2
The lower court held the will valid and identified the heirs, relying in part on a note from a French professor and an opinion from a Monaco advocate. Formally, everything required had been filed: experts had given an opinion on foreign law and reached definite conclusions.
The Supreme Court found two problems with this.
The first was incompleteness. The court had examined only the rule of Monaco law governing the form of a will. But to identify the heirs and their shares, it was necessary to establish the content of the law governing succession to the estate and the circle of heirs. That was not done. An answer to one question (the form of the will) does not dispose of the others (who inherits, and in what share).
The second was the substitution of terms. The foreign experts construed the Russian word for "fund" through the various ways it might be rendered into French. The Supreme Court pointed to the risk of distorting the meaning of a document originally drawn up in Russian. Construing a particular will is a task for the court, not for a translator or a foreign lawyer.
The judgments were set aside and the case remitted for fresh consideration.
What follows from this
An opinion must cover every question of foreign law on which the claim depends. If the claim concerns succession, a single answer about the form of the will is not enough.
And second: an opinion sets out the law; it does not analyse or construe the documents. That is the court's function. This division of roles between the expert, counsel and the court is critical, and it should be kept in mind from the moment the questions to the expert are formulated.
Case two
Swedish limitation and the opinion the courts rejected
Ruling of the Supreme Court of the Russian Federation of 11 March 2021, No. 308-ES20-18927
A creditor under an international supply contract sought to have its claim included in the register of creditors' claims of the buyer. The parties had agreed that matters not governed by the Vienna Convention on Contracts for the International Sale of Goods would be subject to Swedish law. The limitation period turned out to be one of the questions put to an expert.
The creditor filed an opinion from Swedish counsel together with the text of the Swedish statute. Should any doubts remain, it asked the court to order an expert examination or to seek clarification from the competent authorities.
The lower courts did not accept the materials, citing deficiencies in the translation and an incomplete analysis of the possible limitation periods. The applications were refused. The courts did not establish the content of Swedish law themselves. Inclusion of the claim in the register was refused.
The Supreme Court set the judgments aside, holding that doubts about an opinion do not permit the question of the applicable law to be left unexamined. If an opinion has not persuaded the court, the court has other means of establishing the content of the law and must use them. Russian law applies only where the content of foreign law cannot be established despite the measures taken by the court.
What follows from this
For a party: deficiencies in an opinion - even real ones - should not automatically lead to refusal to include the claim. It is worth expressly asking the court to take steps to establish the foreign law and having that recorded in the case file, as the creditor did here.
For a court: a weak expert opinion filed by a party is not licence to decide the dispute under Russian law. The converse is equally true: a party's failure to file an opinion at all is likewise no ground to apply Russian law instead of the foreign law.
Case three
Mastercard, USD 750,000 and English limitation
Case No. A40-282971/2024: judgment of 18 March 2025
A Russian bank paid Mastercard Europe SA a security deposit (approximately USD 750,000) in respect of its obligations as a participant in the payment system. The bank subsequently had its licence revoked and was declared bankrupt, and the right to claim repayment of the deposit passed to TrustVostok LLC.
The security agreement was governed by English law. Three questions of that law arose before the Russian court: whether it permits assignment of the claim, when the right to repayment of the deposit arises, and whether the limitation period had expired.
The agreement contained an arbitration clause providing for disputes to be resolved in London; the Russian court accepted jurisdiction by reference to sanctions-related circumstances and the so-called Lugovoy Law (Articles 248.1-248.2 of the Arbitrazh (Commercial) Procedure Code).
The court took the route expressly provided for commercial disputes: it ordered the parties to submit information on the content of English law. Both sides filed solicitors' opinions.
The defendant objected to the application of the English rules on limitation, arguing that limitation is a procedural matter in English law and therefore not to be applied by a Russian court.
The court considered both opinions and the authorities cited in them, held the content of English law to be established, and rejected the limitation defence. It then went on - no longer relying on the opinions - to assess the evidence of performance of the secured obligations, and granted the claim. The judgment of the Arbitrazh Court of the City of Moscow was upheld on appeal and in cassation.
What follows from this
In this case the roles of the experts and of the court were divided as the law envisages. The opinions helped resolve the dispute about the content of the law. The facts - whether the secured obligations had been performed - the court verified itself.
It is also worth noting that where opinions are filed by both sides, what matters is the precision of the questions posed, the relevance of the rules cited, the completeness of the authorities, and the explanation of any conflict with the opponent's position.
What the three cases have in common
Together, the three cases add up to a set of rules on the use of opinions on the content of foreign law in the Russian courts.
Who is responsible for establishing foreign law
Article 1191 of the Russian Civil Code and Article 14 of the Arbitrazh Procedure Code place the establishment of the content of foreign law on the court. The procedure is set out in detail in Resolution of the Plenum of the Supreme Court No. 23 of 27 June 2017 (paragraphs 42-46).
The parties are entitled to submit references to legislation, court decisions and expert opinions. In claims connected with business activity, the court may, by a separate order, require the parties to produce information on the foreign law. That is what happened in the Mastercard case.
But that obligation does not relieve the court of responsibility for independently assessing the rules of foreign law submitted to it, analysing the facts of the case, and applying the rules established to those facts. It was precisely here, in the Supreme Court's view, that the lower courts went wrong in the case on limitation under Swedish law.
Russian law applies only where the content of foreign law has not been established within a reasonable time despite the measures taken. Two conclusions follow, both already mentioned. A party's failure to file an opinion is no ground to apply Russian law. And filing an opinion does not oblige the court to accept its conclusion: where the other side objects, the court examines the sources and explains its choice.
When an opinion is genuinely needed
A foreign law clause in a contract is an obvious reason to establish the content of that law. But foreign law may be needed even without such a clause. Russian conflict-of-laws rules point to it, and different questions in the same case may be governed by the law of different States. In the succession case, for example, the form of the document and the substantive questions of succession turned out to be governed by different legal systems, and the content of the law had to be established separately for each.
The first step is therefore to determine which law governs each disputed question. The subject matter of the opinion follows from that.
The converse is also true. A cross-border contract does not by itself call for an opinion. Where the applicable law is not in dispute and its content has been reliably established by other means, a separate opinion will most likely be superfluous. An opinion is needed where the parties read a rule differently and the court needs to see how it is applied in practice in the State concerned.
Where the line runs: law or fact
An opinion sets out the content of foreign law. The assessment of evidence and the findings as to what has been established remain the prerogative of the court. Taking assignment as an example (as in the Mastercard case), the line looks like this.
A question of law
What requirements foreign law imposes on an assignment and what follows from a failure to meet them. This is a question that can and should be put to an expert.
A question of evidence
Whether the documents filed by the parties establish the assignment in the particular case. This question is for the court to decide.
An opinion focused on whether the claim has been made out risks helping with neither. It may fail to set out the content of the rule, and the part of it that assesses the evidence will not be accepted by the court. The case about the word "fund" is precisely about this.
What the opinion itself must contain
The opinion should set out the legal questions posed and the answers to them. The rules as in force during the period relevant to the dispute. Their official construction and the practice of their application, together with decisions in comparable situations.
Where foreign practice is not uniform, all the possible approaches must be set out and their significance for the dispute explained. It was precisely an incomplete analysis of the possible limitation periods that the courts held against the opinion on Swedish law.
The opinion must be accompanied by verifiable references to primary sources, any necessary translations, and details of the author's qualifications.
The purpose of preparing an opinion
An opinion on foreign law should help resolve the legal questions on which the outcome of the case depends. For a party, it is the means of putting the applicable foreign rules before the court and of testing the opponent's position. For the court, it is the means of establishing the content of the law without doubts as to how another legal system works.
So before filing an opinion, it is worth asking one question: on the basis of this opinion and the sources attached to it, will the court be able to resolve the relevant question of foreign law itself?
If the answer is yes, the opinion will most likely work, as it did in the Mastercard case. If no, the outcome may be closer to that of the first two cases.
TRP International prepares opinions on foreign law for Russian and foreign courts and for international arbitration. Our experts have experience in preparing opinions on the law of England and Wales, France and Italy, as well as on EU law and public international law.
We help establish the content of the applicable law, analyse the case law and substantiate a position on a specific legal question, and we defend the opinion in the proceedings.
If foreign law applies in your dispute, get in touch to discuss preparing an opinion.
Key sources
Article 1191 of the Civil Code of the Russian Federation
Resolution of the Plenum of the Supreme Court of the Russian Federation No. 23 of 27 June 2017, paragraphs 42-46
Ruling of the Supreme Court of the Russian Federation of 30 January 2024, No. 5-KG23-139-K2
Judgment in case No. A40-282971/2024 of 20 March 2025
Cassation ruling in case No. A40-282971/2024 of 16 September 2025
Ruling of the Supreme Court of the Russian Federation of 11 March 2021, No. 308-ES20-18927