Affidavit of Relationship: Marriage, Common Law, and Sample Letter Templates

An affidavit of relationship is a sworn written statement that documents the nature and history of a personal relationship, most commonly used in immigration proceedings, family court matters, and estate administration. An affidavit for marriage is the specific version submitted to establish a marital relationship for legal or governmental purposes — whether in support of a visa petition, a name change application, or a benefits claim. An affidavit of marriage sample provides a format that individuals can adapt for their own situation, covering the essential elements of the sworn declaration. An affidavit of common law marriage addresses relationships that were never formalized through a civil or religious ceremony — in states that recognize common law marriage, a couple who has lived together and held themselves out as married may need this document to establish their legal status for insurance, inheritance, or immigration purposes. An affidavit of relationship sample letter is a practical starting template that shows the structure, language, and level of detail required for an effective sworn relationship statement.

This guide explains each document type, what it must contain, when it is required, and how to structure it correctly.

Affidavit of relationship: purpose and structure

When this document is needed

An affidavit of relationship is most commonly required in immigration proceedings, particularly when a petitioner is establishing the existence of a qualifying family relationship (spouse, parent-child, sibling) to support a visa or adjustment of status application. The affidavit is also used in probate and estate proceedings when documentary evidence of a family relationship is unavailable or unclear. In some states, it is used in family court to establish parental relationships or in situations where identity documents do not accurately reflect a person’s current family status.

The affidavit of relationship must be written in the first person by someone with direct personal knowledge of the relationship — typically one of the parties in the relationship, a close family member, or a long-term acquaintance who has known both parties over time. The document must identify the affiant, state their relationship to the parties, describe the specific evidence of the relationship they personally know, and include a sworn declaration before a notary public.

Affidavit for marriage: what to include

An affidavit for marriage documents a legally recognized marital relationship. For immigration purposes, the most common use is as a supporting document in spousal visa petitions, where it is submitted alongside documentary evidence (joint bank account statements, shared lease or mortgage documents, insurance beneficiary designations) to establish that the marriage is genuine. The affidavit for marriage itself should state: the full names of both spouses, the date and place of the marriage ceremony, the legal status of any prior marriages (dissolved, annulled, or deceased spouse), the couple’s current shared address, and a list of the supporting documents being submitted alongside the affidavit.

An affidavit of marriage sample for immigration use should be written clearly and factually, avoiding vague language and focusing on verifiable specifics. The tone should be formal but not legalistic — the document is a sworn statement of facts, not a legal brief. It must be notarized to be valid as a sworn document, and should be signed by the party or parties with the most direct firsthand knowledge of the marriage.

Affidavit of common law marriage: state-specific requirements

An affidavit of common law marriage is only legally meaningful in states that recognize common law marriage: currently Texas, Colorado, Iowa, Kansas, Montana, Oklahoma, Rhode Island, South Carolina, Utah, and the District of Columbia, with several others recognizing common law marriages formed before a specific cutoff date. In these jurisdictions, an affidavit of common law marriage documents that the couple has met the legal requirements: that they agreed to be married (a present-tense agreement, not a future plan), that they cohabitated, and that they held themselves out to others as married (using the same last name, referring to each other as husband/wife, filing joint tax returns).

The affidavit of common law marriage must be specific about the evidence of each required element. Generic statements like “we have lived together for many years” are insufficient. The document should name the address or addresses where the couple cohabited, the approximate date they began living together, specific ways they held themselves out as married, and the names of people who knew them as a couple. This document may need to be filed with a state agency or court — consult the relevant state’s family law rules or a licensed family law attorney for the specific filing requirements in your jurisdiction.

Affidavit of relationship sample letter: structure

An affidavit of relationship sample letter follows a standard format: identification of the affiant, statement of the affiant’s relationship to the parties, body paragraphs describing specific observed evidence of the relationship, and a sworn declaration. The body of the affidavit of relationship sample letter should include at minimum: how long the affiant has known both parties, specific events the affiant witnessed (weddings, family gatherings, shared living arrangements), and any direct observations of the couple’s life together. Avoid second-hand reports of what the couple told the affiant — focus on what was personally witnessed or observed.

Pro tips recap: Always notarize relationship affidavits before submission — an unnotarized affidavit is not a sworn document. Consult a licensed immigration attorney or family law attorney before submitting an affidavit of common law marriage or an affidavit for marriage in a legal proceeding, as the specific requirements and formats vary by jurisdiction and purpose. Use the affidavit of relationship sample letter structure as a starting point, then customize with the specific details of the relationship being documented.