A webhook is a method to provide other applications with real-time information. Unlike other APIs there is no need to poll data to keep it up-to-date.
A webhook delivers data to other applications as it happens, meaning you get data immediately. This makes webhooks much more efficient for both provider and consumer.
For any event in the Taxamo system you can register a URL which will receive a notification every time an event occurs in your account. See Taxamo Webhooks for details.