Tanner, of Mansura, La., was described as the "brains" behind an alleged sovereign citizen scheme, though he denied that allegation during a detention hearing in October.
Members of the sovereign-citizen movement claim they are only subject to English common law and don't have to answer to state and federal courts or authorities. They also claim they are not subject to taxation or other actions by the U.S. government.
Tanner and co-defendant Maria Melody Fuentes Cecil Mobo, 42, of Spanish Fork, Utah, were indicted on four counts of mail fraud in August. Mobo is set to go on trial in late February.
Prosecutors alleged the pair filed or attempted to file fictitious liens, claims and judgments against local judges, attorneys and others. An indictment said Tanner instructed Mobo on how to file a "notice of expatriation" in an attempt to exempt herself from various legal proceedings in state courts.
In the plea deal, Tanner admitted that in April he sent Utah County a "Petition for Agreement and Harmony in the Nature of a Notice of International Commercial Claim Administrative Remedy."
He also acknowledged assisting "another" person in similar filings.