The State Tax Commission is reminding Utahns of two changes in the state's sales tax law that took effect July 1.

Among the changes are a revised method for computing sales tax owed on vehicles purchased from private individuals and a requirement that hospital and college cafeterias charge sales tax on meals sold to the general public.Under state law, the sales tax on a vehicle purchased through private individuals, not a retail dealer, will be based on the existing fair market value of the vehicle being sold, not the actual purchase price, said commission spokesman Lee Shaw.

Trade-in allowances will be made only for vehicles given or taken in trade and is also limited to the fair market value of the vehicle. The Motor Vehicle Division will determine the fair market value of the vehicle.

The cafeterias are required to charge sales tax on meals sold to the general public. However, if the cafeterias are limited to employees of the institution only, then the tax exempt status can be maintained. The public, in that case, cannot be allowed access to the cafeteria.