A Ubigi Monthly Plan is a subscription that renews a data plan automatically on your Ubigi account each month. When the data plan is added, you are automatically charged each month on the credit card you registered for it.
When you subscribe to a Ubigi Monthly Plan, you can enjoy the service as long as you want and you can cancel it at any time after a minimum period of 3 months on your Ubigi account. The subscription and its renewal are then cancelled, and the payment is revoked.
The Ubigi Monthly Plan will also automatically be terminated if the payment fails at renewal (ex: when credit card expires).