Divorce, Taxes & Inheritance
A valid common law marriage triggers the same legal consequences as any other marriage.
Once a common law marriage is valid, it carries the full set of legal rights and duties — and ending it requires a formal court process.
Divorce
A common law marriage ends the same way a ceremonial one does: by a court issuing a divorce decree. You cannot simply break up. Property division, support, and custody follow the same rules as any divorce.
Taxes
The IRS and states treat a valid common law marriage as a marriage for filing status. Couples may file jointly or separately as spouses. This matters for brackets, credits, and estate transfers.
Inheritance
A surviving spouse in a valid common law marriage has the same inheritance and probate rights as any spouse. This is precisely why New Hampshire — which otherwise does not recognize new common law marriages — recognizes one for inheritance purposes under RSA 457:39 after a partner dies.
Source
General family-law consequences; see N.H. Rev. Stat. Ann. § 457:39 for the probate-only rule (verified 2026-06).