Understanding What Your Travel eSIM Can Actually Do

One of the most common questions travelers have when considering an eSIM is straightforward: “Can I use it to make phone calls and send text messages?” The answer, however, isn’t as simple as yes or no. It depends entirely on which type of eSIM plan you purchase.

The travel eSIM market is fundamentally divided into two categories: data-only eSIMs and full-service eSIMs (also called voice/SMS eSIMs). Understanding this distinction is crucial for choosing the right connectivity solution for your trip.

The Core Difference: Data-Only vs. Full-Service eSIMs

Data-Only eSIMs: Internet Access Without a Phone Number

A data-only eSIM does exactly what its name suggests—it provides mobile data, functioning essentially like a portable Wi-Fi connection. These plans:

• Provide high-speed internet access for apps, browsing, maps, and social media
• Do not include a phone number for making traditional cellular calls
• Cannot send or receive standard SMS text messages through your phone’s native messaging app
• Are significantly cheaper than full-service alternatives (often by 50-70%)
• Are widely available from providers like Airalo, Holafly, and many others

Think of a data-only eSIM as your internet pipeline abroad—perfect for staying connected online, but not equipped for traditional phone services.

Full-Service eSIMs: Complete Phone Functionality

Full-service eSIMs operate like a traditional phone plan. These plans:

• Provide a dedicated phone number (usually an international or local temporary number)
• Support native cellular calls using your phone’s regular dialer
• Can send and receive standard SMS texts
• Include mobile data as part of the package
• Cost significantly more—sometimes 2-3x the price of data-only plans with equivalent data
• Are less commonly available globally due to complex regulatory requirements

Full-service eSIMs are essentially complete phone lines, giving you the same functionality you have with your regular carrier, just in a different country.

Yes, You CAN Make Calls and Send Texts with a Data-Only eSIM

Here’s the good news: even though data-only eSIMs don’t provide traditional calling and texting, you can still communicate effectively using your internet connection. There are several proven methods:

1. Voice over IP (VoIP) Apps – The Primary Method

Since your data-only eSIM provides internet access, you can use any app-based calling service:

• WhatsApp – Voice and video calls, messaging (most popular internationally)
• Skype – Calls to other Skype users free; can call regular phones for a fee
• Zoom – Video and voice calls
• FaceTime & iMessage (Apple devices) – Automatically work over any data connection
• Facebook Messenger, Telegram, Viber – All function perfectly over mobile data

These apps require only an internet connection, which your data-only eSIM provides. The voice quality is generally excellent on modern 4G/5G networks.

2. Wi-Fi Calling Over Your Travel eSIM Data – The Expert Strategy

This is where things get clever. Most modern smartphones support a feature called Wi-Fi Calling (technically VoWiFi – Voice over Wi-Fi). Despite the name, this feature works over any internet connection, including mobile data from your travel eSIM.

How it works:

• Keep your home carrier SIM active in your phone (but turn OFF data roaming)
• Set your travel eSIM as your primary data source
• Enable Wi-Fi Calling on your home carrier line
• Your phone now routes calls and texts from your home number through the travel eSIM’s data connection

The result: You can make and receive calls using your regular phone number, receive critical text messages (like banking codes), and avoid expensive roaming charges—all while using the cheap data from your travel eSIM.

Configuration Requirements:

• Enable Wi-Fi Calling on your home carrier before leaving your country
• Keep your home SIM active in settings, but disable its “Data Roaming”
• Set the travel eSIM as “Default Cellular Data”
• Your home carrier must support Wi-Fi Calling internationally

This method is particularly valuable for receiving two-factor authentication (2FA) codes, banking texts, and maintaining your regular phone number for important calls.

3. Proprietary In-App Calling Services

Some eSIM providers offer their own calling features within their apps:

• Roamless – Provides in-app calling using VoIP technology
• aloSIM + Hushed – Offers temporary virtual phone numbers
• These typically operate on pay-as-you-go credits, separate from your data package

While convenient, these services currently focus mainly on outbound calling and may not reliably receive inbound calls to a dedicated number.

When You Actually Need a Full-Service eSIM

Despite the workarounds available with data-only eSIMs, certain situations genuinely require native calling and SMS capabilities:

Business Travel Requirements

• Need to make calls to local landlines or businesses that don’t use WhatsApp
• Must provide a local phone number for client communications
• Require guaranteed call quality and reliability for important meetings
• Need to receive inbound calls on a dedicated number

Long-Term Stays or Relocation

• Setting up local services (banks, utilities) that require a local phone number
• Registering for local accounts or government services
• Maintaining professional presence with a local number

Reliability Concerns

• Traveling in areas with inconsistent data quality where VoIP might be unreliable
• Need priority network access (full-service eSIMs often get higher priority than data-only MVNO services)
• Cannot risk communication issues due to work obligations

SMS Verification Requirements

• Need to receive SMS codes from services that don’t accept VoIP numbers
• Some banking and verification systems specifically block calls/texts from VoIP services

Practical Recommendations: Which Should You Choose?

Choose a Data-Only eSIM if:

• You’re a budget-conscious or leisure traveler
• You primarily communicate via WhatsApp, iMessage, or other apps
• You can use the Wi-Fi Calling method with your home carrier
• You’re taking a short trip (1-4 weeks)
• Cost efficiency is your priority

Typical cost: $5-20 for 1-10GB depending on country and duration

Choose a Full-Service eSIM if:

• You’re traveling for business and need a local presence
• You require a reliable local number for inbound calls
• You need to call local landlines or emergency services traditionally
• You’re staying long-term and need full phone functionality
• Budget is less critical than reliability

Typical cost: $25-60+ for similar data allowances with voice/SMS included

A Comparison at a Glance

Feature	Data-Only eSIM	Full-Service eSIM
Mobile Data	✅ Yes	✅ Yes
Phone Number	❌ No	✅ Yes (temporary)
Native Calls via Phone Dialer	❌ No	✅ Yes
Standard SMS Texts	❌ No	✅ Yes
VoIP Apps (WhatsApp, etc.)	✅ Yes	✅ Yes
Wi-Fi Calling Support	✅ Yes (as data source)	✅ Yes
Cost	$ Low	$$$ High
Global Availability	Very High	Limited
Best For	Most travelers	Business/long stays

Important Considerations and Potential Issues

Battery Drain with Dual SIM Setup

When using both your home SIM and a travel eSIM simultaneously, you may experience faster battery drain. This happens because your phone continuously searches for your home carrier’s network while abroad.

Solutions:

• Enable Low Power Mode
• Carry a portable charger
• Turn off your home SIM completely if you don’t need Wi-Fi Calling or 2FA texts

Receiving 2FA Codes

Even with a data-only eSIM, you must keep your home SIM active (with data roaming OFF) to receive SMS verification codes for banking, social media, and other services. These typically arrive as standard SMS texts to your home number, not through the travel eSIM.

Emergency Calls

Emergency services typically require a proper cellular connection with a phone number. With data-only eSIMs, you should use Wi-Fi Calling to your home carrier or ensure you have a way to contact emergency services through alternative means if needed in your destination.

Call Quality on VoIP

While generally good, VoIP call quality depends entirely on your data connection strength. In areas with weak signal or network congestion, you may experience:

• Dropped calls
• Audio lag or echo
• Choppy voice quality

This is why business travelers often prefer full-service eSIMs—native cellular calls are more stable.

The Bottom Line

Yes, you can make calls and send texts with a travel eSIM—but the method depends on which type you buy.

For most travelers, a data-only eSIM combined with VoIP apps and Wi-Fi Calling provides the best balance of affordability and functionality. You’ll save significant money while maintaining virtually all communication capabilities.

For business travelers or those needing guaranteed local phone service, investing in a full-service eSIM provides peace of mind and professional reliability, despite the higher cost.

The key is understanding what you’re actually getting with your eSIM plan before you travel. Always verify whether your chosen plan includes a phone number and native calling, or if it’s data-only. With the right setup, you’ll stay connected throughout your journey without breaking the bank—or experiencing any unpleasant surprises when you try to make that first call abroad.