I don't remember if I paid an annual fee but can confirm that you can turn the service on or off easily on their website whenever you want with no extra fees, you just pay for the months you want at whatever level subscription you want. Once you turn it on, it renews monthly automatically, you need to log in and suspend if you don't want to be billed the next month. It is good for 30 days from when you turn it on before it renews. You can also suspend mid-month and it will stay on for the rest of the 30 days.
There online site is really good, easy to use and you can also change up your fixed messages to say whatever you want.
