You must satisfy 2 conditions: (1) own at least 1,000 BIR and (2) are willing to burn BIR.
Monthly Official Contribution takes place after Monthly Priority Contribution. You can make a priority contribution from 12:00 AM (UTC+7) on the first day of that month.
There may be a case where the remaining BIC won’t equal the one designated for that month.
If BIC is fully redeemed with BIR, that month’s Official Contribution won’t occur.