To apply for a visa to Indonesia, the passport must be valid for at least 6 months on the date of your arrival. For the extension, your passport needs to be valid for at least 6 months as well!
For visas that are valid for a longer period (1 year +), 18 months or more may be required. You can read the details under the requirements section of every visa.
Those entering Indonesia with a (replacement) travel document need 12 months of validity when entering, along with a residence permit.


