Short answer: You are charged ₹ 1 (INR) per active subscriber, per calendar month.
Billing cycle: 00:00 IST on the 1st → 23:59 IST on the last day of each month.
Scenario | Billed? | Notes |
Subscriber imported or added anytime during the month | Yes | Even if added on the 31 st, one full-month charge applies. |
Subscriber is deleted, blocked, or unsubscribed before month-end | No | Status change must occur ≥24 h before 23:59 on the last day. |
Duplicate entry merged | Only 1 billed | Merge detection runs nightly. |