Division of Law Enforcement. RECREATIONAL. The title or transfer document must include the buyer's and seller's names and signatures and the mileage and sales price.All you need is the bill of sale. If you want, you can then use the Maine registration, that will be in your name, to register in Massachusetts. A Massachusetts trailer bill of sale form personifies agreeableness between two (2) parties while determining how to conduct a transaction. Make sure you have a bill of sale with your legal name and legal residential address as SELLER. And their full name and legal address as BUYER. This is a document that records details of a transfer involving a motor vehicle or any other property having some value from a seller to a buyer.