No, you can't back out due to not knowing abou the liens. That (your knowledge, or lack thereof) was under your control: you could, for example, have done a title search yourself in advance to know if you had any "clouds" on title (liens or other issues). You cannot use something under your control--i.e. where you could have found out about the liens in advance, had you chosen to--to get out of a contact. Similarly, you cannot use negative changes in your economic situation--i.e. that something happened or was discovered that will cause you to make less money, or even lose money, on the deal--as grounds to get out of a contract. Your situation is irrelevant to the contract.You can only get out of the contract if the buyer lied about something (committed fraud) or breached/violated their own obligations in an important or material way. Otherwise, and including if you found liens on your property, you are obligated to go through with the contract; if you don't, the buyer can sue you to force you to sell the home.