You can add Data to your existing plan (remaining data will expire on expiry date) or extend your plan with 30 additional days. You have to renew within 90 days after the first thirty days to keep your phone number active. After 90 days without reload your sim card and number will be deactivated permanently.
30 Days extension: we add the corresponding amount to your plan. This amount is credited in USD dollars and will become “available” for the carrier. It is important to not place calls or texts that are not included in your plan. Otherwise the carrier will use this available amount and therefore your plan cannot be renewed because of insufficient funds.
Why is it more expansive to add 30 days rather than purchase a new sim? The initial 30 days prepaid plan is a promotional price. All renewals are paid full price to the carrier Lyca Mobile.