A buying plan in which a customer or club member agrees to accept and pay for products or services announced in advance at regular intervals unless the individual notifies the company, within a reasonable time after announcement not to ship the merchandise.

Negative option is a selling technique in which shipments of goods are made at regular intervals unless the customer sends a refusal notice in advance of each shipment. Most traditional book clubs operated on a negative-option basis, sending a new book each period unless the member told them not to. Some jurisdictions have attempted to ban negative-option programs, in accordance with laws that disallow billing for something that has not been ordered.

Most negative-option sellers mail the customer a reply form and envelope along with a product brochure or catalog describing the next item to be shipped and other items that can be purchased. The customer can either refuse the next shipment, order something instead of the next item to be shipped, or order items in addition to the next item to be shipped. Most marketers do not prepay the postage on the reply envelope, making it less appealing, and less economical, for the customer to send a refusal.