Update: How to Set Up eSIM on Galaxy S21
Your Galaxy S21 can run a travel eSIM next to your regular SIM, so you land with data already working and skip the airport SIM kiosk. This guide covers the full install on Samsung's One UI, works across the S21, S21+, and S21 Ultra, and flags the one part people get wrong: knowing exactly when to switch the plan on.
What you need before you start
Three things:
- A Galaxy S21, S21+, or S21 Ultra — model numbers SM-G991, SM-G996, and SM-G998. All three ship with eSIM hardware.
- Your phone updated to at least One UI 4.0. Older firmware on some units hides the eSIM menu entirely.
- A UROCOMM eSIM profile, delivered as a QR code and activation details by email after purchase.
One quick check first. Open the dialer and type *#06#. If you see an EID number listed alongside your IMEIs, your phone is eSIM-ready. No EID? Scroll to the fallback at the bottom of this guide.
Step-by-step: install eSIM on Galaxy S21
1. Update your software. Go to Settings > Software update > Download and install. Let it finish and restart. This takes a few minutes and it matters — Samsung pushed eSIM menu changes through One UI updates, so an S21 that never updated may not show "Add eSIM" at all.
2. Open the SIM manager. Go to Settings > Connections > SIM manager. On some regional builds this is labeled SIM card manager — same screen, different translation.
3. Tap Add eSIM. You'll see Add eSIM or Add mobile plan. Tap it. The phone connects to Samsung's eSIM server and may take 10–20 seconds to respond. If nothing happens, check your WiFi.
4. Scan the QR code. Choose Scan QR code and point your camera at the code in your UROCOMM email. Printing it or opening it on a second screen both work. If your camera won't read it, tap Enter activation code manually and type the code from the same email.
5. Label the line. Samsung will ask you to name the new plan. Call it something you'll recognize later, like "UROCOMM USA" or "UROCOMM Japan." This matters on a dual-SIM phone — you'll be picking between two lines in settings menus for the rest of your trip.
6. Stop here. Do not turn the line on yet.
That last step is the important one. Read on.
When to activate — and why timing matters
Install the eSIM profile at home. Turn the plan on after you land.
Here's the risk. Most travel eSIM plans start their validity period the moment the line registers on a network, not the moment you bought it. Switch the eSIM on while you're still sitting in your living room, and your 7-day plan may be down to 6 days before you even reach the airport. Worse, if your phone grabs a local tower on a network your plan doesn't cover, you can trigger roaming charges on a plan that was supposed to be prepaid and capped.
So: install now, leave the UROCOMM line switched off in SIM manager, and flip it on once you're past immigration. Airport WiFi or hotel WiFi is a fine place to do it, and it means you're not burning cellular data to download your own activation details.
Planning a US trip? Grab a USA unlimited eSIM before you fly. Heading to Japan instead? The Japan unlimited data eSIM installs the same way. Both follow the same rule — profile in before departure, plan on at touchdown.
Turning it on after arrival
Connect to airport or hotel WiFi, then:
- Settings > Connections > SIM manager
- Tap your UROCOMM line and toggle it on
- Set Mobile data to the UROCOMM line
- Leave Calls and SMS on your primary SIM so your bank can still text you
- If data doesn't connect, turn Data roaming ON for the UROCOMM line only
That last point trips people up. Roaming being on for a travel eSIM is normal — it's how partner networks work. Roaming being on for your home SIM is how you come home to a scary bill. Check which line you're toggling.
Troubleshooting
"Add eSIM" isn't in SIM manager. Usually firmware, sometimes carrier. Run the software update from Step 1 and restart. If it's still missing, your S21 may be a carrier-locked US variant with the eSIM menu disabled by the operator's build. That's not a broken phone. Our Samsung Galaxy eSIM install guide walks through the model-by-model differences, and if your handset simply won't cooperate, a global portable WiFi hotspot gives you the same connectivity without touching your SIM settings.
The QR code won't scan. Use manual activation code entry. Keep the email open on a laptop or a friend's phone rather than the phone you're installing on — you can't scan a code displayed on the same screen you're using as a camera.
eSIM installed but shows "No service." Check three things in order: the line is toggled on, Mobile data is pointed at it, and Data roaming is enabled for that line. Then restart the phone. Nine times out of ten it's the data line setting.
I deleted the eSIM by accident. This is the one irreversible action in the whole process. An installed profile can't be re-scanned from the same QR code — most are single-use. Email service@urocomm.com with your order number and explain what happened. Don't factory reset the phone hoping it comes back; that won't restore the profile.
Coming from an older Galaxy? The menus moved between One UI versions. If you're on an S20, the path is slightly different — see our Galaxy S20 eSIM setup guide.
FAQ
Does the Galaxy S21 support two eSIMs at once? No. The S21 runs one physical SIM plus one eSIM. If you want two eSIM lines active simultaneously, you need a newer handset — our iPhone SE (2nd gen) setup guide covers a device with different dual-SIM behavior, and eSIM-compatible phones lists what else works.
Can I keep my home SIM active while the eSIM runs? Yes, that's the point of dual-SIM. Keep calls and texts on your home line, put data on the UROCOMM eSIM. Just turn off data roaming on the home line so background apps don't quietly bill you.
Will my eSIM work if I travel to a second country mid-trip? Depends on the plan. Single-country plans like a USA eSIM cover one destination. Multi-country trips need a regional plan — the Asia regional eSIM covers multiple countries on one profile. Check the coverage list on the product page before you buy, not after you land.
Wrap-up
The install itself takes about five minutes and six taps. The part that actually determines whether your trip goes smoothly is restraint — set the profile up at home, then leave that line off until you're standing in the arrivals hall.
Not sure which plan fits your itinerary? Browse the full eSIM collection or compare mobile WiFi device options if you'd rather share one connection across a laptop and three phones. Stuck mid-setup? Email service@urocomm.com with your order number and the exact screen you're looking at — screenshots help.
