What is the minimum number of pieces required for USPS Marketing Mail to be considered presorted?

For USPS Marketing Mail to be classified as presorted, a minimum requirement of 200 pieces is established. This threshold is set to ensure that mailings benefit from lower postage rates offered for bulk mailing. The presort process allows the USPS to optimize the handling and delivery of mail by grouping it based on destination, which improves efficiency in processing. By having this minimum number of pieces, USPS can benefit from economies of scale, making it economically viable for both the postal service and the senders. This requirement encourages businesses and organizations to consolidate their mailings, thereby making it easier for the USPS to sort and deliver a larger volume of mail in a more organized manner.