Civil Partnerships Abroad: How the U.S. Handles Property Division, Support, and Recognition Challenges

Civil partnerships/registered partnerships abroad: how U.S. law treats property and support

Couples who entered a civil partnership or registered partnership outside the United States (e.g., UK civil partnership, French PACS, German eingetragene Lebenspartnerschaft, Canadian civil union, etc.) often discover that U.S. rules do not line up neatly with the foreign regime. Inside the U.S., marriage is universally recognized with well-defined consequences for property and support; by contrast, non-marital statuses are treated through a patchwork of federal and state rules. The result is a recognition spectrum: some states treat foreign registered partnerships like marriage for state-law issues; others give them contract-like or quasi-marital effect; and federal systems frequently do not treat them as marriage unless a statute says so.

Recognition theories applied in the U.S.

Comity and public policy

American courts often start with comity: a foreign legal act is respected unless doing so violates strong public policy. Since nationwide marriage equality, hostility to same-sex unions as such has receded; however, registered partnerships may still face hurdles because they are not marriages. Courts ask: What does the foreign status do? If it creates rights analogous to marriage, a state may recognize it for some, but not all, consequences.

Statutory recognition

Several states expressly address out-of-state or foreign registered relationships. California, for example, recognizes substantially equivalent relationships as domestic partnerships if eligibility criteria are met; that triggers community-property rules and spousal-like obligations under state law. New Jersey and a few others extend family-law remedies to civil unions/registered partnerships created elsewhere. Where a state lacks a statute, outcomes hinge on court decisions or general contract and equity principles.

Functional equivalence

Some tribunals use a functional test: if the foreign status looks and operates like marriage (mutual duty of support, dissolution by court, default property regime), treat it like marriage for the issue at hand; if it is a light-touch regime (e.g., PACS), treat it more like a contractual cohabitation with limited family-law remedies.

Property: title, marital/partnership estates, and division

Title vs. equitable ownership

Regardless of status, record title (whose name is on the deed/account) is the starting point—but not the end. Where a state treats the foreign partnership as equivalent to marriage or as a domestic partnership, property acquired during the relationship can be community or equitable distribution property, divided at dissolution. Elsewhere, courts may resort to constructive trust, resulting trust, or unjust enrichment to avoid windfalls if one partner contributed heavily while title sat in the other’s name.

Community-property states

In states like California, Washington, Arizona, Texas, Nevada, New Mexico, Idaho, Louisiana and Wisconsin (marital property), marriage creates a community estate. California also extends community-property rules to registered domestic partners and, by statute, can assimilate substantially equivalent out-of-state/foreign partnerships. That means earnings and acquisitions during the recognized partnership are generally community property, subject to equal division absent agreement. Where a foreign partnership is not assimilated, California courts may still apply quasi-community property concepts to assets acquired while domiciled elsewhere but adjudicated in California at dissolution.

Equitable distribution states

Most states use equitable distribution for marital dissolution. If the forum treats a foreign registered partnership like marriage (or grants civil-union remedies), courts divide marital-type property fairly, considering contributions, need, waste, and length of relationship. If the forum does not extend marital remedies, division may depend on co-ownership, express cohabitation/partition agreements, or equitable restitution.

Movables vs. immovables and choice of law

Classic conflicts rules distinguish between immovables (real estate—governed by the law of the situs) and movables (personal property—often governed by the law of the marital/partnership domicile when acquired). This matters if the couple formed a UK civil partnership while domiciled in England (separate-property baseline) then moved to California (community baseline). Courts may characterize assets as separate/community depending on the time and place of acquisition and then apply quasi-community rules at dissolution.

Support: spousal-type maintenance vs. contract remedies

Statutory maintenance where recognized

If a state grants civil-union/domestic-partnership remedies or recognizes equivalent foreign relationships, courts can award spousal-type support using marital factors: duration, earning capacity, standard of living, age/health, and contributions. New Jersey’s civil-union framework and California’s domestic-partnership statutes are examples of mature regimes with maintenance analogs.

Palimony and contract-based support

In non-recognizing states, courts may still enforce express or implied agreements to provide support (often called palimony), as long as the promise is not based solely on the exchange of sexual services and meets ordinary contract standards. Evidence of shared finances, career sacrifices, or written promises can support quantum meruit or unjust-enrichment awards when statutory alimony is unavailable.

Interstate and international enforcement

Support orders (if available) are enforced across state lines under the Uniform Interstate Family Support Act (UIFSA). If the relationship does not qualify for statutory support, contract judgments can still be enforced under ordinary full faith and credit principles—another reason to put expectations into writing.

Federal systems: taxes, benefits, and retirement

Taxes

For federal income tax purposes, the IRS recognizes marriage (lawful where celebrated) but generally does not treat domestic partnerships, civil unions, or PACS as marriage. Couples in registered partnerships thus often file as single or head of household federally, even if their state treats them as spouses for state tax. California, for instance, requires registered domestic partners to compute state tax on a community basis, which can create complex federal/state mismatches. Meticulous recordkeeping is essential to allocate income, deductions, and credits correctly.

Social Security and veterans’ benefits

Eligibility for spousal or survivor benefits commonly requires a marriage. A foreign registered partnership usually does not qualify unless the federal agency has adopted a special rule or the status has been converted to marriage and meets duration requirements. Couples who rely on these benefits should consider marrying (if they wish to access federal spousal programs) or confirm agency-specific recognition rules before making retirement plans.

ERISA and retirement plans

Employer plans governed by ERISA use federal definitions of spouse. Many plans limit automatic survivor annuities and spousal consents to legal spouses. Partners may still be protected if they are named as beneficiaries, but that protection can be weaker than spousal rights. Review plan documents and submit beneficiary forms early.

Selected foreign regimes and likely U.S. treatment

United Kingdom (civil partnership)

UK civil partnerships are marriage-equivalent domestically. In the U.S., some states extend full marital remedies to foreign civil partnerships; others treat them as domestic partnerships (with state-law consequences) or as contracts. For federal purposes, unless converted to marriage, they are generally not marriages.

France (PACS)

The PACS is a flexible, contract-like regime with tax and property options. U.S. courts that take a functional view may treat it as a cohabitation contract rather than marriage, with limited family-law remedies and heavier reliance on title and agreements.

Canada (civil unions/registered partnerships)

Treatment varies by province. U.S. states with domestic-partnership statutes are the most receptive to assimilation. Elsewhere, couples should prepare for contract and equity analysis rather than automatic marital remedies.

Illustrative graphic — recognition spectrum (conceptual)

Practical playbook for couples relocating to or litigating in the U.S.

• Gather proof: certified copy of the foreign registration, translations, and apostille/legalization as needed.
• Map the forum: identify the state of current domicile and any state where litigation or probate might occur; check statutory recognition.
• Paper the deal: sign a cohabitation/partnership agreement addressing property characterization, reimbursement, and support expectations; add a partition agreement for specific assets.
• Retitle strategically: use joint title or trust instruments; for retirement plans, update beneficiaries.
• Consider conversion: if eligible, marry or convert to marriage to stabilize federal benefits and simplify interstate recognition.
• Plan exits and emergencies: dispute-resolution clauses, forum-selection, and temporary-support provisions reduce chaos if separation occurs.

Conclusion

Foreign civil/registered partnerships occupy a gray zone in U.S. law. For property, outcomes range from full marital treatment (in states that assimilate such unions) to pure contract/equity analysis. For support, some states offer spousal-type maintenance; others confine partners to palimony or unjust-enrichment remedies. Federal systems—taxes, Social Security, ERISA—largely anchor benefits to marriage, creating gaps even where a state recognizes the partnership. Couples can manage risk with documentation, targeted titling, beneficiary planning, and—where it aligns with personal goals—conversion to marriage. A deliberate, paper-heavy approach delivers predictability for relocation, dissolution, and estate planning, while honoring the original foreign status.