The process of tax lien auctions varies from state to state. They all fall into one of the following categories:
Lien state
Deed state
Hybrid state
When a person fails to pay thier property tax the county puts a lien on that property for the tax due plus and associated fees. The owner of the property has a set amount of time to pay the overdue taxes. If the owner fails to pay the taxes within the alotted time then the county will sell the lien at public auction.
In a lien state you are purchasing the lien only from the county. The lein is worth the amount of taxes due by the owner. The owner then has a set period to pay you back for the lein. On top of the initial amount of the taxes the past due property owner would also have to pay you a percentage. Depending upon the state you are in the percentage will be different. If the property owner doesn't pay the lein holder (you) back within the given time then the physical property goes up for aution. You may attend the auction and bid on the proprty but you do not have any priority over other bidders. When whoever wins the auction pays the county your are reinburced for your lien.
In a deed state you are auctually bidding on the deed for the property. The only state I am aware of that is a full deed state is New Mexico. The high bidder of the auction it awarded a deed by the county. At this time the only lein extinguished by the auction is the tax lein. If there were any pre-existing leins on the property (mortgage, home loan, etc.) then those will still exist. So in this type of auction you will need to do significant research.
A hybrid state you purchase the deed, but the owner has a redemtion period to pay back the lien plus interest. This typically results in quicker payment of the lien.
There are also variations of bidding structure from state to state. Some states you are bidding on the actual price you will paythem for the lein, in other states you are bidding on the percent return you are getting on the lien. In the case of bidding on the percent you are starting out at the maximum percent they will give and "Bidding Down" the percent. This is where the premium comes in. For instance say a properties premium is
$3000 and the percent you are bidding starts at 30% you would comete with the other bidders by decreasing your percent. Once the lowest percent has won the winner will then pay the premium and will be issued a lein worth the premium + the % of the premium.
You should always check with your local government for the most accurate information concerning lien auction. You can typically find the county tax assessor's website online. That would be a good place to start looking.
There are also books written specifically on the subject that are of great help in understanding the process.
Tax lien investing can be a safe way to invest with real estate however, as with other real estate investing methods it is not something that will bring a large return of money very quickly. Also do not expect to pick up a $500,000 home for $1000, there will be many other people at the auction and will drive the prices up.