Billion Connect does not provide a Tonga eSIM that includes a phone number or SMS capability. Travelers can only purchase data‑only plans from this provider. However, they can still use VoIP applications such as WhatsApp, Telegram, or iMessage over the data connection for voice and messaging, though some destinations may block or restrict certain apps, so it is advisable to confirm that the services you need are accessible in Tonga before buying a plan.