https://support.knowroaming.com/support/solutions/articles/2100025084-whatsapp-feature-data-usage-explained
Q&A有以下訊息
If you see data charges on your account, it means you have other applications on your device accessing data, since WhatsApp will not appear in your usage history.
Reduce Data Usage from other Apps when using WhatsApp
The following are some articles with suggestions to help reduce data usage on your while traveling.
Reduce Data Usage on iPhone
Reduce Data Usage on Android |