Lost Telcel sim card.

I have been told you can, go to a TelCel store and be prepared to pay for it, it's not horrifically expensive.

I think if you don't keep the number updated, Telcel will cancel your number. One individual said that the expiration time is two months. Another said it was six months. I do know that the number will be canceled as it has happened to me. I am just not sure how long you have. I always recharge my phone at an Oxxo or other store that will allow you to do so but I think you can recharge it online.