Massachusetts businesses should proportionally apply sales tax to shipping charges based on the taxable portion of the shipment. For shipments containing both taxable and non-taxable items, calculate the percentage of the total sale that is taxable and apply that percentage to the shipping fee. For example, if 60% of the items are taxable, then 60% of the shipping charges are subject to the 6.25% sales tax. Accurate allocation ensures compliance and prevents over- or under-taxation of shipping fees. Businesses should maintain detailed records of such transactions to support their tax calculations and reporting.