Are you planning a trip abroad and want to stay reachable under your usual number while avoiding expensive roaming fees? The solution lies in the clever combination of a physical SIM card and an eSIM. This modern Dual-SIM technology allows you to keep your home number active for important calls and SMS, while using a local eSIM for affordable mobile data. In this comprehensive guide, you will learn everything you need to know about using your home number and eSIM in parallel while traveling.
What is Dual-SIM with eSIM?
Dual-SIM technology with eSIM means using a traditional physical SIM card and an embedded SIM (eSIM) simultaneously in one device. The eSIM is a chip permanently integrated into your smartphone that can be digitally programmed – a true revolution for travelers.
Difference between physical SIM and eSIM
The physical SIM card is the classic removable plastic card with stored mobile data. It is inserted into your smartphone’s SIM slot and contains all the information of your mobile contract. The eSIM, on the other hand, is a digital SIM card directly integrated into your smartphone. Instead of swapping a physical card, you simply download an eSIM profile via QR code. The “e” stands for “embedded.”
How Dual-SIM works
On modern smartphones, you can run both SIM types in parallel. Important to know: although both SIMs can be active at the same time, only one can transmit mobile data at a time. However, you can easily switch between them and assign specific tasks – for example, your home SIM for calls and your eSIM for data.
Benefits of Dual-SIM while traveling
The combination of home SIM and travel eSIM offers numerous practical benefits that significantly improve your travel experience.
Massive cost savings
The biggest advantage is the enormous cost savings. While roaming fees outside the EU can quickly reach €10–15 per megabyte, local eSIM rates are often 70–90% cheaper. An eSIM can cut roaming costs by up to 90%, since you surf at local rates.
Reachability on your usual number
You stay reachable under your familiar home number for important calls, SMS, and two-factor authentication while surfing cheaply with the eSIM. This is especially important for banking apps, WhatsApp, and business contacts.
Flexibility and convenience without SIM swapping
Forget the hassle of swapping SIM cards at the airport or searching for local mobile shops. You can install the eSIM at home and activate it upon arrival. An eSIM is ready to use immediately after purchase – no waiting time.
WhatsApp and essential apps keep working
Your WhatsApp number remains unchanged, since it is linked to your home SIM. Two-factor authentication and SMS-based security codes also continue to work smoothly on your German number.
Which devices support Dual-SIM with eSIM?
Most modern smartphones since 2018 support Dual-SIM functionality with eSIM. The technology is now standard among all major manufacturers.
iPhone models with eSIM support
iPhone XS, iPhone XS Max, iPhone XR, and all newer models support eSIM. Notably, iPhone 13 and later even allow the simultaneous use of two eSIMs, without a physical SIM. For full Dual-SIM functionality, you need at least iOS 12.1. To use two different carriers, your iPhone must be unlocked.
Android smartphones with eSIM
eSIM support is widespread among Android devices:
- Samsung Galaxy S20 and newer models
- Google Pixel 3 and later versions
- Huawei P40 and many more
- Most premium smartphones from 2019 onwards
Quick compatibility check
You can easily check if your device supports eSIM: For iOS: go to Settings → Mobile Data → look for “Add Mobile Plan.” For Android: go to Settings → Connections → SIM Manager → look for “Add Mobile Plan.” If these options are available, your smartphone supports eSIM.
Step-by-step: How to set up Dual-SIM perfectly
Preparation before the trip
1. Choose your eSIM provider carefully – research providers for your destination and compare prices, data volume, and coverage. 2. Book the right data plan – as a rule of thumb: 1GB for 3–5 days of basic use, 3–5GB for 1–2 weeks of normal use. 3. Secure your QR code – the provider sends it via email. Important: print it or save it on a second device in case your phone screen breaks.
Installing the eSIM at home
1. Ensure a stable Wi-Fi connection – installation requires Wi-Fi. 2. Scan the QR code – open the camera app and scan. 3. Follow the instructions – the system guides you through, usually in 2–3 minutes. 4. Label your profile clearly – e.g. “Germany Travel” or “USA eSIM.”
Optimizing Dual-SIM configuration
1. Label both SIMs clearly – e.g. “Home Vodafone” and “USA Travel.”
2. Set call preferences – set your home SIM as default for calls and SMS.
3. Configure data settings – set the eSIM as default for mobile data.
4. Disable automatic data switching – very important to avoid your phone switching back to the expensive home SIM.
Activation at your destination
- Activate the eSIM in settings
- Enable mobile data for the eSIM
- Enable roaming for the eSIM
- Keep home SIM active for calls and SMS
What to look for when choosing an eSIM provider
Key selection criteria
Network coverage and quality – check which local operators the eSIM uses. Price transparency – look for prepaid with no hidden fees. German-language support – crucial in case of technical issues. Flexibility – small plans for city trips, larger for longer vacations, reliable networks for business trips.
Regional vs. global providers
German/European providers often offer better support and stricter data protection. International providers may cover more exotic destinations but usually only offer English support.
Understanding tariff models
Prepaid packages: fixed data for fixed time – best for planned trips. Pay-as-you-go: pay per usage – flexible but can be costly. Unlimited: often with a Fair-Use-Policy after a cap.
Signs of a reliable eSIM provider
- GSMA certification
- Transparent terms
- Quick QR code delivery
- Simple installation
- Money-back guarantee
Avoiding cost traps and saving money
Understanding roaming outside the EU
Within the EU, “Roam like at home” applies. Outside the EU, roaming can cost €10–15 per MB. Local eSIMs cut this by up to 90%.
Essential smartphone settings
Disable automatic updates, enable data saver, disable auto data switching, enable roaming only for the eSIM.
Compare providers
Prices vary greatly – comparing can save up to 50%.
Plan your data volume
1GB: emails, WhatsApp, maps for 3–5 days. 3–5GB: social media for 1–2 weeks. 10GB+: streaming or long trips.
Practical travel tips
Before departure
Install eSIM at home but activate later. Backup QR code. Notify key contacts. Save your SIM settings.
At your destination
Activate eSIM after arrival. Test coverage. Contact support if needed. Monitor usage.
Special cases
Emergencies: home SIM works for emergency calls. WhatsApp Business: use two accounts. Banking apps: 2FA still works. Travel groups: share your setup with others.
After returning
Deactivate or delete eSIM. Analyze data use. Note what worked best.
Troubleshooting common issues
eSIM won’t install
Cause: unstable Wi-Fi. Solution: switch to stable Wi-Fi and retry.
No data connection
Cause: roaming disabled or wrong APN. Solution: enable roaming, check APN, reset network settings.
Home SIM not receiving SMS
Cause: roaming fully disabled. Solution: enable roaming for SMS/calls only.
High battery drain
Cause: both SIMs constantly searching. Solution: disable unused SIM temporarily or use power saving mode.
QR code lost
Solution: contact provider, request a new code (sometimes for a fee).
Conclusion: The future of mobile travel
The combination of home SIM and travel eSIM fundamentally changes mobile travel. You stay connected affordably without losing reachability on your usual number. The technology is becoming increasingly user-friendly and affordable.
Main benefits at a glance:
Cost savings: up to 90% less vs. roaming. Convenience: no SIM swaps. Flexibility: separate control for calls, SMS, and data. Security: home number works for banking and 2FA. Instant availability: ready within minutes. With the right provider and setup, Dual-SIM with eSIM is the perfect travel companion for digital nomads, business travelers, and vacationers alike.
FAQ
Can I use two eSIMs at the same time?
Only iPhone 13 and newer support two active eSIMs. For most devices, one physical SIM + one eSIM is standard and sufficient.
Does WhatsApp work with Dual-SIM?
Yes, WhatsApp remains linked to your home number. You can also use WhatsApp Business in parallel.
What if I run out of eSIM data?
You can buy another package or switch to your home SIM (expensive roaming fees apply).
Is my smartphone eSIM-compatible?
Most smartphones since 2018 are. Check Settings → Mobile Data (iOS) or SIM Manager (Android) for “Add Mobile Plan.”
Can I use one eSIM on multiple devices?
No, usually one device only. For device changes, request a new QR code from your provider.
Does eSIM work in remote areas?
Depends on local partner networks. Check coverage before traveling.
Can I cancel an eSIM early?
Most are prepaid and expire automatically. Unused data usually cannot be refunded.
