Once you have come to terms with a Seller your lender will start the ball rolling on getting you a mortgage. If you have not brought in the paperwork the lender requested you have to now.
The transaction is turned over to a title company to make sure there is clear title.
One of the title company’s jobs is to make sure the buyer gets a clear title. The title company perform a lien search to see if any liens, or city / county violations are attached to the property. If there are any the title company will work to get them cleared. If the title company cannot show clear title then they have to inform the Buyer what is not clear. The Buyer can either accept the title issues and has to sign an agreement to assume what is not clear (that does not happen very often) or the transaction can be cancelled by both parties.