Samsung Galaxy S21 Ultra 5G eSIM: compatibility, setup and travel use

This page covers the exact model name Samsung Galaxy S21 Ultra 5G. If you want mobile data abroad without removing your everyday SIM, the short answer is: the model family supports eSIM on eligible regional and carrier versions, but the commercial name alone does not guarantee that every handset has the function. Check the phone itself before choosing a plan.

An eSIM is a digital SIM profile built into the phone. You download it with a QR code, activation code, or supported automatic setup instead of inserting a physical card. For a trip, this can let you keep your regular SIM available while using a separate eSIM for mobile data. Kaspersky eSIM Store is an app and website that helps you choose, arrange, and activate an eSIM with a mobile-data plan for an overseas trip. It is not a mobile operator, network owner, or direct provider of the mobile internet used by a selected plan.

Quick answer for Samsung Galaxy S21 Ultra 5G

Samsung’s current official Galaxy eSIM information lists the Galaxy S21 Ultra among eSIM-capable Galaxy devices. Samsung also warns that eSIM service varies by country and carrier, and that a listed device may not support eSIM depending on its country of origin. Therefore, Samsung Galaxy S21 Ultra 5G is eSIM-compatible when the particular regional, carrier, and software version exposes the eSIM function.

Look for an EID and an Add eSIM option on the phone. If both are present, the current configuration is reporting an eSIM-capable device. If they are missing, do not assume a travel plan, reset, or QR code will make eSIM appear. Confirm the exact model code, market version, carrier lock, and software with Samsung or the original carrier first.

At a glance

Does Samsung Galaxy S21 Ultra 5G support eSIM?

Yes, conditionally. Samsung’s official support material includes Galaxy S21, S21+, and S21 Ultra in the supported family. Its setup guidance uses Settings > Connections > SIM manager > Add eSIM and supports QR-code, automatic, and manual activation. Samsung also explains that a provider may request the EID, found on the phone or its original box. The condition matters because the Galaxy S21 Ultra was sold in multiple markets, with possible differences in firmware, carrier features, and local eSIM availability.

Why regional and carrier versions differ

• Country of origin: Samsung notes that eSIM may not be available depending on where the device originated.
• Carrier and SIM lock: the carrier must allow the plan, and an eSIM-capable phone is not automatically unlocked.
• Firmware and dual-SIM behavior: a carrier build can hide functions, while two active lines can change call, message, and data defaults.

So the safe answer is not “every Samsung Galaxy S21 Ultra 5G works with every eSIM.” It is “Samsung lists the family as capable, and this handset must pass the on-device and plan checks below.”

Check compatibility before choosing a travel eSIM

Use this checklist while you can still contact the seller or carrier:

• [ ] Settings > About phone identifies the intended device; do not rely only on a shortened listing.
• [ ] Settings > Connections > SIM manager shows Add eSIM, Add mobile plan, or an equivalent action.
• [ ] Settings > About phone > Status shows an EID. The exact status submenu can vary.
• [ ] The phone is unlocked, or the original carrier confirms that another eSIM profile is allowed.
• [ ] Wi-Fi or working mobile data is available for installation.
• [ ] Samsung and Android software are current enough for the available menu and activation flow.
• [ ] The plan covers every destination and its data allowance and validity fit the trip.

Verify the EID and eSIM settings

The EID identifies the phone’s eSIM component. It is not the IMEI, serial number, or telephone number. A provider may request it for a pre-assigned plan; a QR-code installation may not require it.

Open Settings > About phone > Status or the SIM/status information area and look for EID. The phone’s current settings are more useful than the box. Then open Settings > Connections > SIM manager and look for Add eSIM. Do not delete a working profile just to test the menu.

If the menu exists but activation is refused, the problem may be the plan, carrier permission, regional restriction, SIM lock, or an already-used QR code. If the EID and menu are both absent, stop before purchase and ask Samsung or the original carrier about the exact model code.

If you need another compatibility check, check your device compatibility before selecting a plan. The result should match the exact regional model whenever possible, not just the marketing name.

How to install and activate an eSIM on Samsung Galaxy S21 Ultra 5G

Before starting, prepare the profile, QR code or activation details, stable Wi-Fi or data, enough battery, and access to the purchase message. Keep the QR code on another screen or print it.

QR-code installation

1. Connect Samsung Galaxy S21 Ultra 5G to Wi-Fi or reliable mobile data.
2. Open Settings.
3. Tap Connections.
4. Choose SIM manager.
5. Tap Add eSIM or the equivalent mobile-plan option.
6. Choose Scan QR code.
7. Point the camera at the QR code supplied for the selected plan.
8. Review the plan details shown on screen.
9. Confirm the download when the details match your purchase.
10. Wait for the profile to download and register.
11. Name the line, for example “Travel data”.
12. Restart the phone if requested, then allow several minutes for registration.

Do not repeatedly scan a single-use QR code after a partial installation. Check SIM manager first. If activation fails, keep the error message and contact the plan’s support channel; never post the QR code or EID publicly.

Manual or automatic installation

Some providers support a pre-assigned plan. Open Settings > Connections > SIM manager > Add eSIM, choose the plan, and follow the prompts. Other plans show Enter activation code; enter only the supplied details. Never substitute an IMEI for an EID.

Samsung’s labels vary across regions and software releases. If you see Add mobile plan instead of Add eSIM, it is the same task. If you see neither, return to the checklist. See the Android installation instructions and the iOS installation instructions; the Samsung steps remain the Android steps above.

Select the eSIM for mobile data

Downloading a profile does not always make it the default data line. In Settings > Connections > SIM manager, select the travel eSIM as the preferred SIM for Mobile data. Keep the home SIM enabled only when you understand its roaming conditions, and turn off automatic data switching until the travel line is tested.

Before departure, install the profile on Wi-Fi and leave it disabled if the plan’s conditions say validity starts on first connection. After landing, enable the travel eSIM, choose it for data, and enable Data roaming for that eSIM when required. Data roaming on the travel line is different from allowing the home SIM to roam, so check the selected line carefully.

Using eSIM for mobile internet while travelling

Install before departure

At home, verify EID and Add eSIM, install the profile, label it, and check when validity begins. Some plans start at installation; others start at first network connection. On arrival, enable the travel line and select it for data.

Activate after arrival

If the plan starts on first use, keep it disabled until needed. At the destination, enable it, set it as the data line, and wait a few minutes. If you have signal but no data, confirm the destination, APN instructions, and selected data SIM.

Use two lines on a longer trip

Keep the home SIM for your usual number and the travel eSIM for data when both carriers allow it. Set separate defaults for calls, messages, and data. On a multi-country route, confirm whether the plan is country-specific, regional, or global.

A travel data eSIM normally does not include a regular telephone number, voice calling, or SMS unless the plan says so. Use messaging and calling apps over data when appropriate. Hotspot availability can depend on the plan and network.

Control data use

Maps, translation, messaging, backups, video, and hotspot use consume data differently. Kaspersky eSIM Store’s app and website help you review destinations and the conditions shown for available plans, then activate the selected eSIM. Use the phone’s data counter, restrict background downloads, and watch remaining data and expiry date.

Common problems and practical fixes

Add eSIM is missing

Check Settings > Connections > SIM manager, look for EID, install available updates, and verify model code and country of origin. If both EID and the eSIM option are absent, treat the phone as unverified and contact Samsung or the original carrier before purchasing.

The QR code will not scan

Increase the other screen’s brightness, remove glare, clean the lens, and keep the full code in view. Confirm that it belongs to the selected plan and has not been used. Use only exact manual details and never share the QR code publicly.

The profile will not download

Reconnect to stable Wi-Fi, complete any captive-portal sign-in, check date and time, and retry from SIM manager > Add eSIM. Confirm plan assignment, payment, and unlock status. A profile installed on another phone may require provider help.

The eSIM is installed but there is no data

In SIM manager, confirm that the travel eSIM is enabled and selected for Mobile data. Turn on Data roaming for that line when required, toggle airplane mode once, and disable automatic data switching. Check destination, expiry, remaining data, APN, and network selection.

Calls or texts use the wrong SIM

In SIM manager, choose the preferred SIM for calls and messages or select the line when dialing. Review home-operator roaming settings before keeping the home voice line active.

The phone is carrier-locked

An eSIM-capable menu does not override a network lock. Ask the original carrier to confirm unlock status and whether another eSIM can be used. If it cannot, use a supported alternative rather than repeating QR scans.

FAQ

Is Samsung Galaxy S21 Ultra 5G eSIM compatible?

Yes, conditionally. Samsung lists the Galaxy S21 Ultra family as eSIM-capable, but country of origin, carrier, firmware, and SIM lock can change the result. Check for EID and Add eSIM on the handset.

Does every Samsung Galaxy S21 Ultra 5G have eSIM?

No guarantee should be made for every regional or carrier version. The commercial name identifies a family, not every market configuration. Missing EID or eSIM settings requires confirmation from Samsung or the original carrier.

Can I keep my physical SIM active?

Usually, an eligible configuration can use a physical SIM and an eSIM, but dual-SIM behavior varies. Set the travel eSIM for data and review call, message, and automatic-switching settings to avoid unexpected roaming.

Do I need an EID for a QR-code eSIM?

Not always. A provider may use the EID for a pre-assigned plan, while a QR code can contain the activation information. EID is still a useful sign that the phone exposes an eSIM-capable configuration.

What is Kaspersky eSIM Store?

Kaspersky eSIM Store is an app and website where users can choose, arrange, and activate an eSIM with a suitable mobile-data plan for an overseas trip. It helps with selection and activation; it is not the operator, network owner, or direct mobile-internet provider.

Key takeaways

Samsung Galaxy S21 Ultra 5G can use eSIM on eligible regional and carrier versions. The dependable decision comes from three checks: the phone exposes an EID, SIM manager offers Add eSIM, and the handset is permitted to use the selected plan. Country of origin, firmware, carrier support, and SIM lock can change the result even when Samsung lists the family as compatible.

Install over a stable connection, keep the QR code private, assign the new profile to mobile data, and enable data roaming only for the travel eSIM when required. Test the line before depending on it for maps, tickets, work, or messaging.

Final device check and trip eSIM choice

Before paying for a travel eSIM, open Settings > About phone > Status and confirm an EID. Then open Settings > Connections > SIM manager and confirm that Add eSIM is available on the exact Samsung Galaxy S21 Ultra 5G. Check that the phone is unlocked, software is current, and the plan covers every destination. Confirm its data allowance, validity, activation timing, roaming requirement, and support conditions.

After those checks, use the Kaspersky eSIM Store app or website to choose an eSIM and a suitable mobile-data plan for the overseas trip. Install it while dependable Wi-Fi is available, leave it disabled if the plan calls for later activation, and select it as the data line when you arrive. This device-first sequence keeps the exact model and its regional limitations in view.