Lex Lata and Lex Ferenda: What the Terms Mean and Why the Distinction Matters in Turkish Commercial Disputes

The distinction sounds academic, yet in a Turkish commercial dispute it decides which rules a judge must apply, what a pending bill or a Constitutional Court challenge can and cannot change, and how arguments about the 'better' rule should be framed. This guide explains both terms and shows where the line runs under the Turkish Constitution, the Civil Code and the transitional rules of the Code of Obligations, the Code of Civil Procedure and the Criminal Code.

Two Latin terms, one practical question

Lex lata is the law as it currently stands: the statutes, regulations and other binding rules in force on a given date. Lex ferenda is the law as it should be or as it may become: reform proposals, draft bills, recommendations in legal writing, and arguments that an existing rule is unfair or outdated. The two expressions come from Latin, literally “the law that has been made” and “the law that is to be made”.

Lawyers use the pair, sometimes without naming it. When a contract is drafted, the drafter works with lex lata. When a client asks whether an announced reform will rescue a claim, the honest answer separates what the law says today from what it might say tomorrow. When counsel argues that a statute should be read in a particular way because the legislator would have wanted it, the argument sits on the boundary between the two.

The distinction matters most where money is at stake and time is short: a commercial debt that must be collected, a foreign judgment or arbitral award to be enforced in Türkiye, a fraud complaint, a medical-tourism malpractice claim or a shareholder dispute. In each of these, the first legal question is not what the ideal rule would be, but which rule binds the court today and which version of it applies to facts that happened years ago.

This guide explains the two terms and shows how Turkish law draws the line between them in five places: the duty of the judge, the way a bill becomes law, gap-filling under the Civil Code, the transitional rules on time, and the effect of Constitutional Court decisions.

Lex lata in Turkish law: what binds the judge

The starting point is the Constitution. Under Article 138(1), judges are independent in the performance of their duties and give judgment in accordance with the Constitution, statute and law and their personal conviction. Article 138(2) adds that no organ, authority, office or individual may give orders or instructions to courts or judges, send them circulars, or make recommendations or suggestions about the exercise of judicial power.

Two consequences follow for a commercial client.

1. The court’s yardstick is the law in force. A judge is not free to apply a rule simply because it would be fairer or more modern. Arguments about the better rule are not irrelevant, but they must be anchored in the existing text, its purpose or a gap in it.
2. Policy statements are not law. Announcements by ministries, draft regulations circulated for comment and political statements about future reforms do not instruct courts. Under Article 138(4), it is the other way round: the legislature, the executive and the administration must comply with court decisions.

The Turkish Civil Code (TMK) states the same principle for private law. Under TMK Article 1(1), the statute applies to all matters it addresses by its wording and its spirit. The phrase “wording and spirit” (sözüyle ve özüyle) is important: the law in force is not only the literal text, but also the meaning that the text carries. A great deal of argument in commercial litigation takes place here, inside lex lata, about what the existing words and their purpose require.

From lex ferenda to lex lata: how a rule enters into force

A reform proposal becomes binding law only by passing through the constitutional procedure. Under Article 88(1) of the Constitution, members of parliament are entitled to propose laws, and the procedure for debating proposals in the Grand National Assembly is governed by its Rules of Procedure (Article 88(2)).

After the Assembly adopts a law, the President publishes it within fifteen days (Constitution Article 89(1)). Within the same period the President sends back to the Assembly for reconsideration, with the reasons given, any law whose publication the President does not find wholly or partly appropriate; budget laws are not subject to this provision (Article 89(2)). If the Assembly adopts the returned law again unchanged by an absolute majority of its total members, the President publishes it (Article 89(3)).

For a party to a dispute this sequence has a simple meaning: until the law is adopted, published and in force, it is lex ferenda. A bill that would extend a time limit does not save a claim that is about to become time-barred under the current law. A draft regulation that would simplify a procedure does not excuse a party from following the existing procedure. Planning a case on the assumption that a pending reform will pass, and pass in the expected form, is a risk the client should take knowingly, if at all.

Gaps in the law: when the judge acts as legislator

Lex ferenda has one recognised entry point into the courtroom in private law. TMK Article 1(2) provides that where the statute contains no applicable provision, the judge decides according to customary law and, if there is no custom either, according to the rule the judge would lay down if the judge were the legislator. Under TMK Article 1(3), the judge draws on legal scholarship and court decisions when deciding.

This is a narrow door, and it opens in a fixed order:

1. first, the statute, read by its wording and its spirit (TMK Article 1(1));
2. second, customary law, where the statute has no applicable provision (TMK Article 1(2));
3. only then, a rule that the judge frames as if acting as legislator (TMK Article 1(2)).

For a party to a case, this means that a lex ferenda argument is strongest when it is presented as an argument about a genuine gap: the facts fall outside any applicable provision, and the proposed rule is the one a reasonable legislator would adopt, supported by legal writing and decisions. It is weakest when it asks the court to set aside an applicable provision because a better one is imaginable.

A related limit applies to the Constitutional Court itself. When it annuls a law or a provision, the Court may not act as a legislator and create a rule that would lead to a new application (Constitution Article 153(3)). Filling the gap left by an annulment is the task of the Assembly.

Time and the law: which version applies to old facts

A commercial dispute may concern events that took place years before the hearing, and the law may have changed in between. Turkish law answers the question “which version applies?” differently depending on the field. The table below summarises the rules discussed in this guide.

Contracts: Law No. 6101

The current Turkish Code of Obligations (Law No. 6098) replaced the former code, and a separate law, Law No. 6101 on the Entry into Force and Application of the Turkish Code of Obligations, regulates the transition. Under Article 1 of Law No. 6101, the acts and transactions that took place before the new Code entered into force, whether they are legally binding and their consequences are, as a rule, governed by the law in force when they took place. However, default, termination and winding-up occurring after the new Code’s entry into force are subject to the new Code.

Article 2 makes an exception for the new Code’s rules on public order and morality: they apply to all acts and transactions regardless of the date on which they took place. Article 5(1) deals with time limits: limitation and forfeiture periods that started to run before the new Code entered into force remain subject to the old law, but if the remaining part is longer than the period in the new Code, the period expires when the new Code’s period has run from its entry into force. Article 7 provides that the new Code’s public order and morality rules and its Articles 76 (interim payments), 88 (interest), 120 (default interest) and 138 (excessive difficulty of performance) also apply in pending cases.

The structure of Law No. 6101 is a useful model for thinking about any change of law in a commercial relationship: the formation of a long-term contract may be governed by one law, while a default that occurs later is governed by another.

Procedure: immediate application

The Code of Civil Procedure (HMK, Law No. 6100) takes a different approach. Under HMK Article 448(1), its provisions apply immediately, provided that they do not affect completed steps. A new procedural rule therefore governs the next steps in a pending case, but it does not undo a step that was validly completed under the old rule.

Criminal law: the more favourable law

Where a commercial dispute has a criminal side, for example a complaint of fraud or breach of trust, Article 38(1) of the Constitution and Article 7 of the Turkish Criminal Code (TCK) apply. No one may be punished for an act that was not an offence under the law in force when it was committed, and no heavier penalty may be imposed than the one provided at that time. Under TCK Article 7(1), no one may be punished for an act that is no longer an offence under a later law; if a sentence was already imposed, its execution and legal consequences end automatically. Where the law at the time of the offence and a later law differ, the law more favourable to the offender is applied and executed (TCK Article 7(2)). Under TCK Article 7(3), rules on the execution regime apply immediately, except those on suspension of sentence, conditional release and recidivism.

Constitutional review: when a party challenges the law in force

Sometimes the client’s position is not that the law should change in the future, but that the provision in force is unconstitutional. Turkish law gives a route for this inside an ongoing case.

Under Article 152(1) of the Constitution, if the court hearing a case finds a provision of a law or Presidential decree that it must apply to be unconstitutional, or is convinced that a party’s claim of unconstitutionality is serious, it stays the case until the Constitutional Court decides. If the court does not find the claim serious, the claim is decided by the cassation authority together with the merits (Article 152(2)). The Constitutional Court gives its decision within five months of receiving the matter; if it does not, the trial court concludes the case under the provisions in force, but if the Constitutional Court’s decision arrives before the judgment on the merits becomes final, the court must comply with it (Article 152(3)). Where the Constitutional Court has rejected a claim on the merits, no new application claiming that the same provision is unconstitutional can be made until ten years have passed from publication of the rejection (Article 152(4)).

If the Constitutional Court annuls a provision, Article 153 sets the consequences:

• the Court’s decisions are final, and annulment decisions cannot be announced without a written reasoning;
• the annulled law or provision ceases to be in force on the date the decision is published in the Official Gazette, unless the Court sets a later date, which may not exceed one year from publication;
• where the entry into force of an annulment is postponed, the Assembly debates and decides with priority on a proposal to fill the resulting gap;
• annulment decisions do not have retroactive effect;
• decisions are published immediately and bind the legislative, executive and judicial organs, the administration, and natural and legal persons.

The practical lesson is that a constitutional challenge is a tool with fixed timing. It can change the outcome of a case that is still open; it does not reopen a matter already decided, because an annulment does not reach back.

Using the distinction in a commercial dispute

For foreign companies and individuals with interests in Türkiye, keeping lex lata and lex ferenda apart leads to a few working rules.

1. Fix the date of the facts first. Before arguing about the content of a rule, establish when the contract was concluded, when the default occurred, when the time limit started, and when any alleged offence was committed. The transitional rules above attach different consequences to each of these dates.
2. Read the provision in force in full, including its amendments. Turkish statutes can be amended over time, and the version on the date of the facts may differ from the current one. The consolidated text and its footnotes show when each change took effect and whether a provision was annulled.
3. Treat reform proposals as information, not as a defence. A pending bill may signal where the law is heading, but deadlines and procedural obligations under the current law must be met on the assumption that the bill may never pass.
4. Frame “better rule” arguments as interpretation or gap-filling. Within lex lata, the statute is applied by its wording and its spirit (TMK Article 1(1)); a rule the judge creates as legislator is available only where there is no applicable provision (TMK Article 1(2)).
5. Raise constitutional objections early. A claim of unconstitutionality can only influence a case while it is pending, and the Constitutional Court’s decision must arrive before the judgment on the merits becomes final for the trial court to be bound by it (Constitution Article 152(3)).

Lex Lata takes its name from this distinction: our work starts from the law as it stands. Read more about the office, or about how we approach commercial debt and asset recovery in Türkiye.