MobileSIM eSIM Data Plans for Japan

MobileSIM does not provide a truly unlimited data eSIM for Japan. The plans named “Japan Unlimited data for X days” actually give a 3GB/day allowance, after which the speed is throttled to 1000kbps. Because of this fixed daily cap, the plans are not considered unlimited high‑speed data. Travelers who need larger, unrestricted data may choose one of MobileSIM’s fixed‑data plans, such as the Japan 20GB for 30 days plan or the Japan‑covered 100GB plan available for 180 days. These fixed data options offer a larger total allowance and can be more cost‑effective for users who consume more data than the 3GB/day limit.

MobileSIM does not provide eSIM plans for Japan that include a phone number or SMS service. The provider only offers data‑only eSIM options in Japan, so travelers cannot use local voice or text services from the device.

To communicate while traveling, you can rely on internet‑based apps such as WhatsApp, Telegram, and iMessage. These apps work over the data connection and allow calls and messaging without needing a local phone number or SMS capability.

MobileSIM offers 12 single‑country (Japan‑only) plans and 22 multi‑country plans that include Japan. The plans are priced between $2.34 and $89 and provide data from 200 MB up to 100 GB over 3 to 180 days. Plans are split into daily data‑cap options, which limit the amount of data you can use each day, and fixed data‑cap options, which allocate a set amount of data for the entire validity period.