Japan & South Korea eSIM

Look up your phone’s exact model number with the manufacturer to see if it’s listed as compatible, and make sure your phone is not carrier-locked. Seeing an EID number or an “Add eSIM” option in your settings is a good sign, but some phones have regional restrictions. If you’re not sure, please contact our support team before you buy.

Look up your phone’s exact model number with the manufacturer to see if it’s listed as compatible, and make sure your phone is not carrier-locked. Seeing an EID number or an “Add eSIM” option in your settings is a good sign, but some phones have regional restrictions. If you’re not sure, please contact our support team before you buy.

No. An eSIM can be installed only once, and it locks to the first device it is installed on. It cannot be moved to another phone, re-scanned, or reinstalled afterward, and it is non-refundable once installed. Please install your eSIM on the device you plan to keep using. If you are switching devices and need help, contact our support team.

Yes. With Cellesim you top up the eSIM you already installed. You do not scan a new QR code, you do not install a second profile, and your phone number setup does not change.

Open the Cellesim app or your account page, pick a top-up for the eSIM you are using, and the data is added to the same line. The validity period is extended at the same time, so a 7-day plan topped up on day 5 keeps running instead of expiring.

This matters most when you are already travelling: running out of data usually means you have no connection to buy more with. Because the top-up lands on the existing profile, it works as soon as it is processed, without Wi-Fi and without reinstalling anything.

If an eSIM does not work and you have not used the data, we refund it in full to the original payment method. There is no restocking fee and you do not need to return anything.

In practice we check the line on the carrier side first, because most failures are a stuck data session that we can restart remotely in a few minutes. If the line genuinely cannot be made to work in your location, we refund.

To be straightforward about the limit: once a plan has been used, a refund is no longer possible, because the data has already been bought from the network operator on your behalf. In that case we look at a replacement instead. If a plan was never activated, the refund is simple.

Yes. Every Cellesim account has a wallet balance, and you earn 5 USD of store credit for each friend who buys their first eSIM with your referral link.

The credit lands in your wallet automatically once their order completes, and it is applied to your next purchase — you do not need a coupon code. Wallet balance never expires.

Your referral link is in your account. There is no limit on how many people you can refer, and the person you refer also gets a discount on their first order.

Cellesim includes a free VPN with every active eSIM. It is not an add-on, a trial, or a paid upgrade: as long as you have an eSIM plan that is still valid, the VPN is available at no extra charge.

This is unusual in the travel eSIM market. Most providers sell data only, and you buy a VPN separately from a VPN company. A few bundle a paid VPN subscription. With Cellesim the data plan and the VPN come from the same purchase.

It matters because mobile data abroad does not solve everything. Public Wi-Fi in airports and hotels is unencrypted, some services are restricted depending on the country you are connected from, and banking apps behave differently on foreign networks. The VPN covers that part.

Almost always, yes — usually by an order of magnitude. Standard carrier roaming outside your home region is commonly billed per megabyte or as a daily pass of 10-15 USD. A travel eSIM is a prepaid data plan bought at local wholesale rates.

A concrete comparison: a 5 GB / 30-day plan for a single country averages about 28 USD across our catalogue. A daily roaming pass at 10 USD reaches that after three days, and keeps charging.

The exception is regional roaming that your carrier already includes for free — EU-to-EU roaming for EU customers, for example. If your plan covers the country you are visiting at no extra cost, use it. Everywhere else, prepaid data is cheaper.

Less than most guides tell you. Across 278 of our own travel eSIMs, the median customer used 96 MB per day. The average was 158 MB, and even heavy users at the 90th percentile stayed under 350 MB a day.

That means for a one-week trip:

• 1 GB covers a typical traveller — maps, messaging, occasional browsing
• 3 GB is comfortable if you post photos and videos daily
• 5 GB or more only if you stream video or work off mobile data

The common advice of "1 GB per day" reflects home usage on Wi-Fi-free devices, not travel. Most hotels, cafes and airports still give you Wi-Fi for the heavy things. Buy small, and top up if you are wrong — that is cheaper than paying for data you never use.

Buy and install before you fly. Activate after you land. These are two different steps and confusing them is the most common mistake.

Installing writes the profile onto your phone and needs an internet connection — which you have at home and may not have at the airport. Activation happens automatically the first time the eSIM connects to a network at your destination, and that is when the validity period starts counting.

So installing early costs you nothing: a 7-day plan installed three days before departure still gives you 7 full days from the moment you land. Waiting until you arrive means standing in an arrivals hall trying to find Wi-Fi to install a product you already paid for.