The objectives of this research are (1) to find and analyze whether promotional flyers on social media by fast food restaurants are classified as agreement clauses and (2) to provide a complete description of the responsibility of business actors for losses incurred by consumers on the price differences stated in the promotional pamphlet and paid at the cashier based on the Consumer Protection Law. The research method used by researchers is empirical legal research. The empirical legal research method is a legal research method that serves to see the law in real terms and examine how the law works in the community. The results of this research indicate that: (1) Promotion through pamphlets on social media by fast food restaurant business actors is not only a marketing tool but also an agreement clause between business actors and consumers. Price offers and food menus listed in promotional pamphlets are considered valid offers and purchases by consumers of the promos can be used as binding sales and purchase agreements. Fast food restaurant businesses have an obligation to provide clear, accurate, and not misleading information to consumers in every promotion carried out (2) The Consumer Protection Law gives responsibility to business actors to provide correct, clear, and not misleading information to consumers, including in terms of price promotions. Business actors are obliged to state prices clearly and are responsible for the correctness of the prices stated. If there is a price difference between the promotion and the paid at the checkout, the business actor may be subject to administrative sanctions or even criminal sanctions.