Postbye helps consumers cancel subscriptions and other services through formal letters sent by certified mail. Customers search for the company they want to leave, provide their name and address, and review their cancellation letter before paying. Postbye prepares the letter with account details and a clear request to terminate the subscription, stop future charges, and, where applicable, delete personal data or remove stored payment methods. Each order is prepared promptly and mailed by the next business day.

The service includes certified-mail tracking and signed delivery proof, which Postbye emails to the customer when the letter is delivered. It also follows up to check whether the company accepted the cancellation and shares the result. Postbye lists providers such as Netflix, Planet Fitness, Comcast, Adobe, Spotify, Hulu, and Amazon Prime among its popular cancellation destinations. Its process is designed to offer customers documentation of their request and delivery, without requiring them to manage the mailing themselves. Customer reviews and reported cancellation volumes are featured on the site.