Staying connected in Vietnam: APN, top-ups, apps and VPN

Yes, in principle. Viettel runs an official online top-up service specifically for people outside Vietnam to recharge a Vietnamese Viettel number, plus top-up through the Viettel Shop portal. In practice, though, foreign Visa/Mastercard cards are sometimes rejected by Viettel's own payment system even when an "international card" option is shown — results vary by card, and some travellers instead use third-party international mobile-reload services, which work but add a markup. A number also needs to have completed Vietnam's identity verification requirements to avoid being blocked, including while used abroad.

Telegram is blocked: Vietnam's Ministry of Science and Technology ordered telecom operators, including Viettel and VNPT, to block it in May 2025, and it has stayed inaccessible on Vietnamese networks since (implementation isn't always perfectly consistent). WhatsApp, Messenger, Signal, Viber and Zalo are not blocked and work normally over a Vietnamese SIM or eSIM, no VPN needed. Traffic routed through a roaming/international gateway rather than a Vietnamese network may behave differently — worth confirming for a specific eSIM rather than assuming it matches local-SIM behavior.

Using a VPN in Vietnam is not clearly protected by law but is widely tolerated in practice — commercial VPN services are openly marketed for use there. For an ordinary tourist using a VPN for privacy, work or hotel Wi-Fi security, the practical risk is low, and there's no evidence of routine enforcement against ordinary VPN users. Vietnam's enforcement focus has been on specific platforms and content (for example blocking Telegram outright) rather than prohibiting VPN technology itself; Decree 147/2024 (effective December 2024) did strengthen government powers over online platforms and user data more broadly. A VPN doesn't make otherwise unlawful activity lawful and doesn't guarantee anonymity.