Extend SIM Validity
Keep your Indonesian number alive without buying credit. Pay with Visa, Mastercard, Apple Pay, Google Pay, iDEAL, Bancontact, or Wero, usually done within 1 minute.
Indonesian Phone Number
Validity only
This only adds validity to the SIM. No credit and no data are added, so your balance and quota stay as they are. A number whose validity runs out is blocked by the operator, even with credit left on it.
Tri: the days do not add up, the new validity replaces the current one.
Telkomsel: the total validity can be at most 360 days. An extension that would go past that is refused and your payment comes back automatically.