Is a Notary or a "Bill of Sale" Needed? If the seller failed to disclose a lien or serious flaw in the item's condition, the buyer's word will not be enough to get compensation.The MVA provides a Bill of Sale form. Complete and sign the Title Application Form 130-U. Signed bill of sale is required for trailers and vehicles 25 years old and older. You can file your mechanic liens in person at the following Montgomery County Prothonotary office locations: Office of the Prothonotary P.O. BOX 311