What Is LTE Calling? How VoLTE Works and When to Use It

LTE calls typically refer to LTE voice (VoLTE): making and receiving regular phone calls over your carrier’s 4G LTE network. LTE stands for “Long Term Evolution.” You simply use your existing phone number and the built-in “Phone” app—no need to download a separate calling app. Smart’s VoLTE guide explains this in detail.

For most people, the practical decision is simple: as long as your phone and carrier support VoLTE, keep the feature turned on. It offers clearer sound quality, faster call connection speeds, and supports mobile internet access during calls. However, an LTE signal alone does not guarantee that your specific device and rate plan support voice calls.

Additionally, LTE calling does not provide you with an extra phone number or an online text message inbox. These features serve different purposes, which is important to note if you only want to receive verification codes rather than make calls.

How LTE calling works

Your phone converts your voice into small digital data packets and sends them over the LTE network. Your carrier uses a system called the IP Multimedia Subsystem (IMS) to manage calls.

The network can assign specific Quality of Service (QoS) treatment to voice traffic. Simply put, it handles real-time calls differently from background downloads because voice latency is immediately noticeable. ETSI’s VoLTE Quality Assessment Report describes voice-dedicated logical connections and the independent processing of call signaling.

This does not mean your call will monopolize a radio frequency. Voice and other data can use the same LTE wireless network; they are simply handled differently within that network.

VoLTE is a form of IP voice (VoIP) managed by mobile carriers. Calling apps also use IP to transmit voice, but they operate as standalone services over available internet connections. VoLTE calls, however, remain part of your mobile carrier’s telephone service.

Does the other person need VoLTE?

The recipient does not have to use VoLTE simply to receive your call. Carriers can connect calls to other mobile networks and landlines. For example, Smart lists mobile, landline and international destinations for its VoLTE service.

The audio quality you hear still depends on the complete connection. A high-quality link from your phone to your carrier cannot guarantee equally clear audio through every network and device involved.

What changes when you use VoLTE?

The main advantages are related to how calls are connected and the actions you can take during a call:

Clearer call quality: Compatible connections support higher-quality audio.
Faster call setup: These calls may connect faster than calls that require switching to the legacy voice network.
Simultaneous use of voice and mobile data: You can use maps, check orders, or browse the web while on a call.

These are features, not guarantees. Rogers’ VoLTE FAQ lists clearer audio quality, faster connection speeds, and the ability to continue using LTE data during calls as some of the benefits of their service.

For small business owners, the ability to use voice and data simultaneously is particularly useful. You can talk to a customer on the same phone while checking delivery information. For travelers, this means you can still use navigation features while on a call.

VoLTE does not improve the strength of the cellular signal reaching your phone. Poor signal coverage, network congestion, or other issues along the call path may still affect your call experience. Changing your voice settings will not resolve all call dropouts or audio issues.

LTE calling, Wi-Fi calling and calling apps compared

These options can look similar because all let you speak through a phone. The useful distinction is which service handles the call and how your device connects to it.

Calling method	Connection from your device	Service used	Practical use
VoLTE	Carrier’s 4G LTE network	Your mobile carrier’s voice service	Regular calls where compatible LTE service is available
Wi-Fi calling	Wi-Fi connection	Your carrier’s supported Wi-Fi calling service	Regular calls where cellular reception is weak
Internet calling app	Wi-Fi or mobile data	The app provider’s calling service	Calls supported by that app, subject to its features and charges
Voice over New Radio, or VoNR	Compatible 5G standalone network	Carrier voice service	Voice over 5G where the phone and network support it

Wi-Fi calling requires carrier and device support; connecting to Wi-Fi alone does not enable it. Apple’s Wi-Fi calling instructions explain how supported iPhones can make regular calls with little or no cellular coverage.

VoNR is the corresponding voice technology for 5G standalone networks. A phone supporting 5G standalone does not automatically support every carrier’s VoNR implementation, as Xiaomi’s explanation of VoLTE and VoNR notes. Treat the 5G icon as a network indicator, rather than proof of which technology carries a particular call.

Does LTE calling use data or cost extra?

VoLTE transmits voice as data packets, but this technical fact does not determine how carriers bill for calls.

Carriers typically treat VoLTE calls as regular voice calls. Take Rogers, for example: the company states that its VoLTE calls will be deducted from the voice minutes included in a customer’s plan. The company also states that roaming calls will be billed according to the applicable roaming plan. Rogers’ billing guidelines explain why you should carefully review your voice service terms rather than assuming calls will use up your data allowance.

Before making a call that could be expensive, confirm the following:

Whether the destination is included in your voice plan.
Whether international calling rates apply.
Whether you are roaming and what roaming charges apply.
Whether you are using the carrier’s “Phone” app or a standalone internet calling service.

Enabling LTE calling does not mean international calls are free. Browsing the web or streaming content during a call will also use additional data.

What you need for LTE calling

To use VoLTE properly, simply having a phone labeled “4G” is not enough. Please verify the following four aspects of the service:

Device Support: The specific model of your phone must support the VoLTE service provided by your carrier.
Eligible Number: Your carrier must have enabled the service for your subscription plan and a compatible SIM or eSIM card.
Adequate Network Coverage: You must be in a location with access to a network that offers this service.
Compatible Software: Your phone’s operating system and carrier settings must support the carrier’s specific implementation of the service.

Smart’s setup checklist includes: an LTE SIM card, adequate network coverage, an up-to-date compatible smartphone, and a valid calling plan or subscription service.

Additional checks are required for imported phones. Two devices with the same retail name may have different regional models or software versions. Rogers specifically highlights these model differences. Please provide customer service with the exact model number, rather than just the product name.

A helpful question to ask is: “Does this specific model support VoLTE on my current line?” This is more precise than simply asking if the phone supports LTE.

How to check or enable LTE calling

Menu names vary by phone, software version, carrier and country. Some carriers enable VoLTE automatically, so a missing switch does not necessarily indicate a problem.

On an iPhone

Open Settings.
Tap Cellular, which may be labeled Mobile Data or Mobile Service in some regions.
Select the relevant line if your phone has multiple lines.
Look for Cellular Data Options and Voice & Data, where available.
If a VoLTE option appears, enable it according to your carrier’s instructions.

Apple says the available LTE and Voice & Data controls depend on the iPhone model, carrier and region. Use its cellular settings guide alongside your carrier’s device instructions.

If the phone offers automatic network selection, you generally do not need to force LTE-only mode to use VoLTE. Ask the carrier before changing network modes to troubleshoot a calling problem.

On Android

On supported Samsung devices, the documented route is:

Open Settings.
Tap Connections.
Tap Mobile networks.
Enable VoLTE calls, if the switch is available.

This route comes from Samsung’s support instructions. Other Android manufacturers may place similar controls under SIM settings or Network & internet. Searching Settings for “VoLTE” can help locate the relevant menu.

If you cannot find the control, check your carrier’s guide for the exact model. Avoid treating instructions for another Android phone as a guaranteed match.

Make a practical check

After confirming the settings:

Choose the line you want to test.
Place a normal call from the built-in Phone app in an area with good coverage.
Check whether the call connects and audio works in both directions.
If mobile data is part of your plan, try opening a lightweight webpage during the call.

Record what happens rather than relying only on an icon. On a dual-SIM phone, note which line handles the call and which line supplies data. If you need a definitive answer about VoLTE registration, ask your carrier to check the line.

What to do when LTE works but calls fail

A working internet connection does not prove that your carrier’s voice service is available. Use the symptom to narrow the next check.

Symptom	What to check next
Mobile internet works, but calls fail	Ask the carrier to verify voice service and VoLTE support for the exact device and line.
No VoLTE switch appears	Check whether the carrier enables it automatically or uses another setting name.
Calls fail only in one location	Check local coverage and whether the carrier reports a service issue.
Calls fail only abroad	Confirm voice roaming support for the destination, partner network and device.
Calls work, but mobile data stops	Check VoLTE support and, on dual-SIM phones, the selected data line.

Install available phone and carrier updates before escalating the issue. When contacting support, provide the model number, software version, location, affected line and whether incoming calls, outgoing calls or both fail.

That information is more useful than repeatedly switching random network settings. It also helps distinguish a device compatibility problem from a local coverage issue.

Can you use LTE calling internationally?

Distinguish between two scenarios: making international calls from within the country and using your cell phone while abroad.

When making international calls from within the country, you can use the VoLTE service via your local network. Whether you’re allowed to make these calls and what the rates are depend on your calling plan.

Using VoLTE while roaming requires additional conditions to be met. Your domestic carrier, the network you’re accessing, and your device must all support the relevant protocols. Telstra’s roaming guide explains that VoLTE availability depends on its roaming partners. Do not assume that using LTE data abroad will necessarily guarantee that voice calls will work properly.

Before you travel, please confirm that your destination and your phone model support this feature. Please check the compatibility of emergency calls separately, especially when using imported devices. Telstra clearly distinguishes between standard VoLTE functionality and emergency call support on its network.

In areas where the legacy voice network has been shut down, disabling VoLTE may result in the loss of essential calling options. Please follow your carrier’s guidance rather than arbitrarily disabling this feature simply to avoid potential data charges.

Does LTE calling affect SMS verification?

LTE calls refer to voice services. SMS verification involves the sending of text messages containing a verification code (commonly known as a one-time password, or OTP).

If calls are working normally but you have not received the verification SMS, this does not necessarily indicate a VoLTE issue. Please check the phone number and country code, confirm whether you can receive regular text messages normally, and review the delivery instructions for the service you requested. Please follow the specified retry interval and do not repeatedly request the verification code.

Additionally, please confirm that you have selected SMS verification rather than the method that provides a verification code via voice call. SMS reception services should not be assumed to support voice calls by default.

Where temporary and rental numbers fit

A virtual phone number for receiving messages serves a different purpose from enabling voice calls on your existing mobile line. BEE-SMS offers online SMS reception through temporary numbers and number rentals. It can be a relevant option for permitted SMS verification, authorized software testing and business workflows that need a separate receiving number.

Choose the access period around the task:

Number option	Intended use	Decision to make before ordering
Temporary phone number	Short-term SMS verification	Can you complete the permitted task within the available access period?
Rental number	Extended access under the applicable rental terms	Will the available term cover your expected need for later messages?

If you need to rent a phone number for repeated authorization tests or ongoing workflows, please review the current options on the BEE-SMS Rental Page. Before making a payment, please confirm service and country availability, validity period, renewal conditions, and SMS limits.

A longer rental period does not imply permanent ownership, nor does it guarantee future verification success. Third-party platforms may reject certain types of numbers, and text messages may fail to deliver. You should only use temporary numbers if you are prepared to accept that the number may become inaccessible later. For critical accounts, please arrange for a permanent recovery method permitted by the platform.

An online inbox allows you to receive text messages online without providing your primary mobile number to the service. However, this does not guarantee anonymity or account security, nor does it resolve voice call coverage issues on your mobile phone.

Choose the service that matches the problem

For ordinary mobile calls, start by confirming VoLTE support for your device and line, then leave it enabled as your carrier recommends. For weak indoor cellular reception, check whether supported Wi-Fi calling meets your needs.

For a missing OTP, investigate SMS delivery and the requesting platform’s requirements. If the task calls for a separate receiving number, choose temporary access or a rental based on how long you will need it. Keeping those decisions separate makes troubleshooting faster and reduces the chance of buying a service that does not address your problem.