A lien on someone’s property indicates that there’s some sort of debt that must be paid off. A seller can get hit with a tax lien if he or she fails to pay back taxes or property taxes. If the owner of the house ignores a lien, he or she could ultimately face foreclosure and a bank could seize the house to cover the unpaid debts.
Buying a house with a lien on it likely won’t be possible, particularly if you’re taking out a mortgage. To remove the lien, the seller would have to pay what’s owed or work out an agreement with their creditor.