A Practice Note discussing the Illinois state lien registry established by the State Tax Lien Registration Act that is maintained by the Illinois Department of Revenue (IDR). This Note addresses the effect of liens filed with the state lien registry, including state tax liens filed by the IDR and liens filed by the Illinois Department of Employment Security (IL DES) for unemployment benefit contributions. This Note also discusses the need for lien searches of both the county recorder's records and state lien registry, the perfection and attachment of liens, requesting an IL DES letter of clearance, and escrows for IL DES contribution liens.