Not happy with a contractor’s work on your house? Watch out! If you refuse to pay the invoice, you risk having a mechanic’s lien attached to your property. If you haven’t heard of a mechanic’s lien or don’t understand the implications of a mechanic’s lien, you may want to continue reading. A lien creates an interest in your property to secure the performance of an obligation — in this case, the payment of a debt to a contractor.