The quick answer is, usually, no. Generally when you sell your car, you won't need to worry about notarization.For most private vehicle sales between individuals, a bill of sale does not need to be notarized to be considered legally valid and binding. Bills of sale do not require notarization in the state of Illinois, but it is always an option. Although some states require a bill of sale during the transaction, it is entirely optional in Illinois. Six states actually require that a bill of sale be notarized before it can be used to transfer the title of a vehicle. If the title does not contain a Notice of Sale form, it may be down- loaded at ilsos.gov. In many cases, you are not legally obligated to notarize a bill of sale. Does a vehicle bill of sale have to be notarized in Illinois? No. When you privately sell a car in Illinois, the Bill of Sale does not need to be notarized.