Flat rate shipping is a shipping method where the cost of shipping is not connected to the weight, shape, or size of the shipped item. Instead, it is based on how much you can stuff into the USPS-issued box or envelope. Flat rate shipping is a popular option for small businesses because it offers a lower, predictable cost, and eliminates the need to weigh packages to calculate shipping costs. USPS Priority Flat Rate is a shipping option provided by the US Postal Service that offers 1-3 day shipping services with fixed rates for packages with a maximum weight of 70 lbs. USPS offers flat rate envelopes and boxes that come in standard sizes to accommodate various sized items. The advantages of flat rate shipping include easy use, no need to weigh or measure every package, and no complicated calculations. Flat rate shipping can be a cost-effective option for small businesses by having a lower, predictable cost, and better forecasting finances without getting caught off guard by surprise shipping costs. However, flat-rate shipping methods may not always be the fastest or cheapest option, and it may not cater to the unique needs of every merchant.