Can I send one announcement to every parent at once?

Yes. Bulk announcements go over Telegram to recipients who have linked the bot, and each recipient draws one broadcast credit from the school's balance. Announcements never travel the official WhatsApp route: their category is marketing, and that route is not the place for it.

Transactional messages — invoices, reminders, payment confirmations, schedule changes — use no broadcast credit and never stop along with an empty announcement balance.