Sweden has approved a major reform of its marriage laws by introducing a prohibition on cousin marriages and certain other marriages between close relatives. The legislation was approved by the Swedish Parliament (Riksdagen) on 26 May 2026 and will enter into force on 1 July 2026. While the reform is primarily a family law measure, it may also have major repercussions for immigration and family reunification cases. This is because many residence permit applications rely on the existence of a legally recognised marriage. For immigration practitioners, affected families, and individuals planning to relocate to Sweden, understanding the scope of these changes is becoming increasingly important.

Legislative Background

The reform is contained in:

• Government Bill (Proposition) 2025/26:154, Förbud mot kusinäktenskap och äktenskap mellan andra nära släktingar
• Civilutskottets betänkande 2025/26:CU33
• Parliamentary decision adopted by the Riksdag on 26 May 2026
• Entry into force on 1 July 2026

The amendments affect both:

• The Swedish Marriage Code (Äktenskapsbalken)
• The Act on Certain International Legal Relationships Concerning Marriage and Guardianship (Lag 1904:26 s. 1)

The purpose of the legislation is to strengthen protection against marriages between close relatives and to establish clearer rules regarding the recognition of foreign marriages.

Why Was the Law Introduced?

According to the government, the reform aims to:

• Strengthen individual autonomy and personal freedom in marriage decisions
• Protect vulnerable individuals from family pressure and coercion
• Promote consistency in Swedish family law
• Prevent circumvention of Swedish marriage rules through marriages performed abroad
• Align recognition rules with Sweden’s broader public policy objectives

The government concluded that cousin marriages should no longer be accepted as a legally recognised form of marriage in Sweden, regardless of where the marriage took place.

What Will Change From 1 July 2026?

The most significant change is that marriages between cousins will generally no longer be permitted or recognised in Sweden. The reform extends beyond marriages celebrated within Sweden. It also affects foreign marriages that would otherwise be valid under the laws of another country. Historically, Sweden has often recognised marriages that were validly entered into abroad, even when the same marriage could not have been entered into under Swedish law. The new legislation significantly narrows that approach in relation to cousin marriages and certain other close-relative marriages. As a result, a marriage that is fully lawful in another jurisdiction may nevertheless fail to receive legal recognition in Sweden.

Why Is This Important for Immigration Cases?

The legislation does not directly amend the Swedish Aliens Act (Utlänningslagen). However, immigration authorities frequently rely on the legal validity and recognition of a marriage when assessing applications. If a marriage is not recognised under Swedish law, the legal basis for the immigration application may be weakened or removed entirely. For this reason, the reform may have substantial indirect consequences in migration matters.

Areas Potentially Affected

Residence Permits Based on Marriage

Many applicants obtain residence permits as spouses of Swedish citizens or residents. If the marriage is not recognised in Sweden, the applicant may face difficulties establishing the family relationship required under immigration legislation.

Family Reunification Applications

Family reunification applications frequently depend upon proof of a legally recognised marital relationship. Where recognition is denied, Swedish authorities may need to assess whether another legal basis exists for granting residence rights.

Extension Applications

Individuals who already hold residence permits based on marriage should carefully review their circumstances. While transitional protections are expected to apply in many cases, the exact impact may depend on the individual facts and the legal status of the marriage before 1 July 2026.

Registration with Skatteverket

Recognition of a foreign marriage often involves registration of marital status with Skatteverket. The new rules may affect whether certain marriages can be registered after the legislation comes into force.

Other Legal Consequences

Recognition of marriage affects more than immigration.

It can also influence:

• Inheritance rights
• Property ownership rights
• Pension entitlements
• Tax matters
• Social security rights
• Family law proceedings
• Next-of-kin status

The consequences therefore extend well beyond residence permit applications.

Transitional Provisions

One of the most important aspects of the reform concerns existing marriages. The legislation is not intended to automatically invalidate every cousin marriage that already exists.

Marriages Entered Into Before 1 July 2026

Marriages entered into before the new law is enforced are generally expected to benefit from transitional protections.

The exact legal position may depend upon the following:

• Where the marriage took place
• Whether it has already been recognised in Sweden
• Whether it has been registered with Swedish authorities
• The specific circumstances of the parties involved

Foreign Marriages Already Recognised in Sweden

Foreign cousin marriages that have already been recognised or registered in Sweden before 1 July 2026 are expected to enjoy stronger protection under the transitional framework.

Foreign Marriages Not Yet Recognised

Greater uncertainty may arise where a cousin marriage has been legally performed abroad but has not yet been recognised in Sweden before 1 July 2026. These cases are likely to require individual legal assessment under the new recognition rules.

What Should Affected Families Do?

Individuals who may be affected should consider reviewing their circumstances before the legislation takes effect.

This is particularly important where the following are true:

• The marriage is between cousins
• The marriage took place outside Sweden
• Registration with Skatteverket has not yet occurred
• A residence permit application is being prepared
• A family reunification application is planned
• An extension application will be submitted after 1 July 2026
• The marriage forms the primary basis of the immigration claim

Early preparation may help identify potential issues before an application is submitted.

What Should Immigration Advisors and Legal Practitioners Consider?

Immigration advisors, jurists, and legal representatives should pay close attention to the interaction between family law and migration law.

Future case assessments may require consideration of:

• Whether the marriage is recognised under Swedish law
• Whether transitional provisions apply
• Whether alternative grounds for residence exist
• Whether family life rights under Article 8 of the European Convention on Human Rights may become relevant
• Whether proportionality considerations arise in individual circumstances

As the law begins to be implemented, further guidance from Migrationsverket and the Swedish courts will likely be important in clarifying its practical application.

Conclusion

The prohibition of cousin marriages represents one of the most significant recent developments in Swedish family law. Although the legislation primarily concerns marriage and family law, its effects may extend into immigration and family reunification matters because legal recognition of a marriage is often a fundamental requirement for residence-based applications. Individuals who are currently relying on a cousin marriage, or who intend to do so in future immigration proceedings, should carefully assess their position before 1 July 2026. As with many legal reforms, the practical consequences will ultimately depend on how the legislation is interpreted and applied by Swedish authorities and courts in individual cases.

Disclaimer: This article provides general legal information only. It is not legal advice. Every immigration case is different, and the outcome depends on the individual facts, evidence and the law applicable at the time the decision is made.