What are tax lien certificates and how are they purchased?

Tax lien certificates, variously known as tax executions, certificates of purchase, and tax sale certificates, are instruments offered for sale by local county and municipal governments as a method of recovering property tax dollars deemed delinquent due to the property owner's failure to satisfy the debt. The issuance of tax certificates to investors is typically done in an auction setting where the successful bidder is determined by the lowest interest rate declared or the highest bid for cash.