If you haven't been using your Etisalat SIM for 3 consecutive months, you will be charged 10 AED for every 3 months of not use if you want to have a lifetime validity. If there is no balance of 10 AED, your line will be disconnected and the number retained for a duration of 12 months. Within this 12 month period you can start reusing the line of you recharge and start using. If no usage during this 12 month duration, the line will be deactivated and it cannot be revived again.