If the IRS wants to file a statewide tax lien against a taxpayer’s personal property, the document evidencing the lien will be filed with the secretary of state’s office. Most states (if not all) index the IRS liens along with the UCC-1 financing statement liens. Although the tax lien is indexed with the UCC filings, the tax lien is not a UCC filing.
The reasoning for indexing the federal tax liens with the UCC-1 filings has to do with a potential bankruptcy filing by the debtor/taxpayer. In most cases, there will be an issue of which lien takes priority in the bankruptcy case. The date of filing with the secretary of state usually decides the issue of priority.