If an Iridium prepaid account is not recharged with a new airtime voucher BEFORE its current expiration date, the account will automatically become expired and enter the 270-day* Grace Period. Upon account expiration, ALL unused minutes will be expired from the account and the account will have zero balance. Inbound or outbound calls will NOT be possible during the grace period.
Under no circumstances any expired prepaid balance can be restored once an Iridium account expires.
The Grace Period is 270 days from the date of prepaid account expiration. During the grace period, a new airtime voucher can be purchased and loaded to the same SIM-card without incurring a reactivation fee. The new prepaid account balance and validity time will be equal to those associated with the new voucher. The new account will also have the same Iridium phone number.
After the 270-day grace period ends, Iridium will automatically deactivate the SIM-card. A $250 reactivation fee will be assessed in order to reactivate the SIM-card, no exception. The previous Iridium phone number is NOT guaranteed for the SIM after the Grace Period ends, although Iridium does not usually reuse phone numbers for at least 2-3 months after SIM deactivation.
* Until April 5, 2017, the grace period was 90 days.