yaySIM does not provide a Belgium eSIM that includes a local phone number or SMS capability. Their Belgium plans are data‑only, so travelers cannot receive or make voice calls or send text messages through the network.
If a traveler needs to communicate while in Belgium, they can use popular VoIP applications such as WhatsApp, Telegram, or iMessage over the data connection. However, some destinations may block or restrict certain apps, so it is advisable to confirm that the services they rely on are accessible in Belgium before purchasing a plan.