The pre-arrival declaration is completely free. The only official site is https://prearrival.immigration.gov.vn (ending in .gov.vn).
- Many look-alike sites (with names like "vietnam prearrival" or "arrival card") are run by private agents that charge fees or collect card details.
- The official site does not ask for payment to submit a declaration.
- E-visas should likewise only be applied for on the official site https://evisa.gov.vn.
- If you paid a fake site: contact your bank to block the card and submit again on the official site.