whats flat rate shipping refers to a shipping option where the cost is the same regardless of the weight or destination of the package. Flat rate shipping is commonly offered by postal services like USPS, which has flat-rate boxes for shipping items within the United States and internationally. This pricing model is beneficial for businesses and individuals who are shipping heavy items, as they can avoid higher shipping costs based on weight or size. Flat rate shipping can be convenient for budgeting and helps customers know the cost upfront.