While a bill of sale is generally valid without notarization, there are situations where it becomes a wise precaution. Proof of ownership normally includes a bill of sale.The DMV does not provide a form for a bill of sale. During this 30-day grace period, the owner is required to have aboard the vessel a bill of sale with proof of the date of purchase. Motor Vehicle, Mobile Home, Off- Highway or Vessel Description. Year. The bill of sale must list the Trailer Identification Number (TIN). We can even assist with VIN verification or bill of sale issues with the Hillsborough County Tax Collector.