Proving an Ancestor Never Naturalized: The USCIS Certificate

Several citizenship-by-descent routes hinge on a fact that lives entirely in US records, not European ones: whether your immigrant ancestor ever became an American citizen. Programs such as German, Irish, and Italian descent can require proof that the ancestor did not naturalize, because a naturalization at the wrong moment could have broken the chain of citizenship passed to the next generation.

What the certificate is

When no naturalization record exists, you ask US Citizenship and Immigration Services to confirm that absence in writing. That confirmation is the Certificate of Non-Existence, requested through Form G-1566. In effect, USCIS searches its records and issues an official statement that it found no naturalization for the named person.

Who can request it

• A deceased subject of record, including someone born at least 100 years ago
• A living subject who consents to a USCIS response
• The subject of record requesting their own file
• Anyone who received a USCIS Genealogy letter instructing them to file

How US applicants file

Download Form G-1566 from the USCIS website, complete it carefully following the official instructions, sign it, pay the fee, and mail it to the designated USCIS lockbox. The request must go by mail; it cannot be filed online. You can include multiple individuals' forms in one envelope as long as each case is clearly separated. Supporting evidence is required, for instance a death certificate or obituary for a recently deceased subject.

Fees and common rejections

The G-1566 form itself is free, but a filing fee applies, with the paper-filing fee higher than the online figure quoted for related genealogy requests. Fee waivers exist for qualifying filers and must be requested by mail. Files commonly get bounced for mailing to the wrong location, mixing unrelated forms, inconsistent personal details across forms, the wrong fee, or an outdated edition of the form. Slowing down to match every detail prevents weeks of delay.

This is general information, not legal advice; requirements differ by destination country. Run the free eligibility check to see your path.