"AutoBook" is our automatic booking feature. If you have AutoBook enabled, then our service will automatically book an earlier slot when it locates one for you. This means you don't need to sit eagerly waiting by your phone for a notification to come through that you may need to respond to. The alternative to AutoBook is our Manual booking system. With Manual Booking, we will send you an SMS notification with the cancellation slot test details that are available. We can only hold slots for around 10 minutes, so you need to reply with "BOOK" within those 10 minutes for us to attempt to get that slot for you. AutoBook takes the hassle away!