Gather around children for a tale of royal power. Far back in history the king owned everything. (Does that remind you of Donald Trump?). Occasionally the king would grant property to a duke. Property ownership meant wealth, so the king would demand that the duke pay yearly taxes. To this very day much of the money that supports government comes from property taxes, for you see children, government is still king.
If the property owner fails to pay the tax the county government places a lien on that property. Every year property tax liens are sold at auction to the highest bidder. If the property owner fails to satisfy that tax lien the new owner of the lien can begin foreclosure and acquire the property. That seldom happens, but it is possible. Usually the liens are redeemed (paid) before the time limit expires.
You've probably seen the TV infomercial extolling the benefits of buying property tax liens. It's true, property tax liens usually pay an above average rate of interest (it varies from state to state) and the lien is secured by some kind of real estate.
Because of the infomercial and real estate seminars, tax lien investing has became very popular. There was a time in some counties when few people would show up at the property tax lien auction. These days the seminar gurus often arrive with bus loads of students ready to bid.
A good investment, yes, but there are some surprises for the uninformed. Because property tax sales occur each year, there may be liens on the same property, for different tax years held by different investors. Like this... Bill bought the 1980 lien; Hillary bought the 1981 lien and George was the successful bidder the next year when the 1982 liens were offered.
Here in Arizona the law is very clear that tax liens for different tax years held by different private parties have parity among themselves. So if the redemption period for Bill's 1980 tax lien had expired without being paid he could foreclose on the property, but his foreclosure would not wipeout the liens held by Hillary and George. Bill might have a right to the property, but he could not get clear title until he pays off Hillary and George.
If Hillary and George had been influenced by that infomercial and thought that they could scoop up ownership of property for the simple price of a tax lien, well they are more than a little disappointed.
Oh, there could be one more surprise. Sometimes the state owns tax liens. When the state government forecloses all other privately held property tax liens are turned into waste paper.
Property tax liens certainly can be a good investment if you always keep one fact one mind... You are the duke and the government is the king!