Can you use WiFi Calling on a plane? Airplane Mode, in-flight Wi-Fi and airline call rules

This question has three layers. First, can the phone do it? Second, does the aircraft's Wi-Fi network let WiFi Calling traffic through? Third, does the airline allow it? Each layer has a different answer. This article takes them one at a time, then shows how to prepare your Thai number before boarding so you do not miss important calls or OTP codes.

Can you use WiFi Calling on a plane?

The phone can do it, but in most cases you cannot actually use it: many airlines ban or block voice calls over onboard Wi-Fi, and aircraft Wi-Fi networks often do not let WiFi Calling register with your mobile carrier.

WiFi Calling (the standard name is VoWiFi) places calls on your normal mobile number over the internet instead of a cell tower. The phone builds an encrypted IPsec tunnel to a carrier gateway called the ePDG, then registers with the same IMS core that VoLTE uses. Because it does not need a cell tower, it can work with Airplane Mode on, as long as Wi-Fi is switched back on and actually reaches the internet. That is why many people assume WiFi Calling should work on a plane.

On a plane, though, there are more gates to pass than at home. You need to buy or log in to the airline's Wi-Fi pass, the aircraft has to be above the altitude where the system switches on, the network must not block the ports WiFi Calling uses, and finally the airline's rules have to allow talking on the phone in the cabin. If any one of these fails, the call does not happen.

What WiFi Calling is and how it works

Can you turn Wi-Fi on while in Airplane Mode?

Yes. Apple states that Airplane Mode turns off all radios except Bluetooth, and that if the airline allows it you can still use Wi-Fi and Bluetooth in Airplane Mode. Android works the same way: tap the airplane icon in Quick Settings, then tap Wi-Fi to turn it back on. The cellular radio stays off, and the cellular radio is the part most flight rules want switched off.

One thing to know: many phones remember the choice. If you turned Wi-Fi on during Airplane Mode last time, Wi-Fi may stay on the next time you switch Airplane Mode on. Check the status bar icons before take-off so you know what is actually on.

Airplane Mode plus Wi-Fi is also the same recipe Thai carriers give for using WiFi Calling abroad. True-dtac tells customers to turn on Airplane Mode, connect to Wi-Fi and check that the WiFi Calling symbol appears before calling. AIS advises checking that "AIS WiFi Call" shows on screen before dialling, so the call does not go out over normal roaming. On the ground this recipe works well. On a plane, the same recipe still runs into the network limits and airline rules below.

1. 1Turn on WiFi Calling while still in ThailandTrue-dtac says WiFi Calling must be switched on while you are in Thailand, or it cannot be used. On iPhone: Settings > Cellular (or Mobile Data) > Wi-Fi Calling; with two lines, pick your Thai line first. On most Android phones it sits under SIM and mobile network settings, or in the Phone app > Settings. Menu names vary by model and carrier.
2. 2Test it on the ground before boardingAt the airport or at home, turn on Airplane Mode, turn Wi-Fi back on, and look for "Wi-Fi" next to the carrier name or the WiFi Calling icon. Then make a short test call. If it does not show up on the ground, it will not show up in the air.
3. 3Finish anything that needs an OTP before the flightIf you have a bank transfer or identity check that needs an SMS OTP, finish it before the aircraft door closes. Do not plan on receiving an OTP in the air.
4. 4Set a reply message or tell likely callersTell family or work how many hours you will be in the air and ask them to message you instead. If your carrier offers voicemail or missed-call alerts, check that they are on.

Airplane Mode and mobile data, explained

Why doesn't WiFi Calling show up on in-flight Wi-Fi?

Even where an airline has no written ban, WiFi Calling often fails to register on aircraft Wi-Fi for these technical reasons.

• Not logged in yet: most aircraft Wi-Fi starts with a portal page where you log in or buy a pass. Until then the phone is connected to Wi-Fi but cannot reach the internet, so WiFi Calling cannot register.
• Messaging-only passes: free or cheap passes are often limited to text chat apps. Emirates, for example, gives Skywards members free WhatsApp, Facebook Messenger and other text messaging for the whole flight. WiFi Calling's IPsec traffic is not on that list.
• Blocked ports: WiFi Calling needs UDP 500 (IKE) and UDP 4500 (IPsec NAT traversal) open to the carrier's ePDG. If the network filters these ports, or deliberately blocks voice traffic, the WiFi Calling icon never appears.
• System not on: Singapore Airlines says in-flight Wi-Fi is available once the aircraft is above 10,000 feet (about 15 minutes after take-off, until about 15 minutes before arrival), and may be unavailable over countries that have not authorised the service or over areas with no connectivity such as polar regions.
• The home carrier filters it: research on VoWiFi geoblocking found that some operators worldwide block WiFi Calling connections arriving from certain continents or IP ranges. Aircraft Wi-Fi reaches the internet through the satellite provider's ground stations, which may be in a different country from the one you are flying over. That study did not test Thai carriers, so it cannot say whether AIS, True or dtac filter this way.
• High latency: older geostationary satellite systems add a lot of delay, so even if WiFi Calling registers, the voice can lag or break up. Low-Earth-orbit systems such as Starlink have far lower latency.

We found no official Thai carrier page that says outright whether WiFi Calling works over aircraft Wi-Fi. If you do see the WiFi Calling icon in the air, that only means the network let it register. It does not mean the airline allows you to talk on the phone.

Which airlines ban calls over in-flight Wi-Fi, and which allow them?

Call rules on planes come from two places. The first is government rules on cellular radios: in the US, FCC rule 47 CFR 22.925 prohibits operating cellular phones while an aircraft is airborne, to protect ground networks from interference. The second is the airline's and the Wi-Fi provider's own policy on internet calls, which mostly bans them to keep the cabin quiet rather than for flight safety.

A clear example: in 2012 a Delta passenger was escorted off the aircraft after making a call through a VoIP app on the onboard Wi-Fi. Delta explained that voice apps were prohibited by the terms of service of Gogo, the Wi-Fi provider, not directly by an FAA rule. From the airline's point of view, WiFi Calling is just another way of talking on the phone, so it falls under the same rules.

For Thai Airways and other airlines Thai travellers use often, we could not open the Wi-Fi policy pages on the day we checked, so they are not in the table. Read the terms on the onboard Wi-Fi login page, or ask the crew. A rule that holds for almost every airline: if the terms do not say calls are allowed, assume they are not.

In Europe, the European Commission decided on 24 November 2022 to let airlines offer 5G on board through pico-cell equipment, building on a framework that since 2008 has allowed messaging, phone calls and data on planes. It is an option for each airline, not an obligation, and it covers onboard mobile service, not WiFi Calling.

How is WiFi Calling different from in-flight roaming and calling apps?

There are three ways to reach people from a plane, and they get mixed up. The first is WiFi Calling: your Thai number over the aircraft's Wi-Fi. The second is in-flight roaming: some aircraft carry their own mobile network, and your phone joins it as a normal roaming network. The third is apps such as LINE, WhatsApp or FaceTime, which call through an app account rather than a phone number.

AIS states on its On ground & In-flight roaming page that customers can use roaming on board, including internet, calls to Thai numbers, receiving calls and sending SMS, but only on some airlines and routes. If the aircraft supports it, the phone picks up the onboard roaming network and AIS sends an SMS to confirm. This is a roaming service billed under a roaming package or roaming rates, not WiFi Calling, and it only works with Airplane Mode off.

Can you receive SMS and OTP codes on a plane?

Do not plan on it. Technically, once WiFi Calling registers, SMS for your Thai number can travel over Wi-Fi through the IMS core (SMS over IP), and the GSMA's IR.51 profile covers voice, video and SMS over Wi-Fi. On a plane, though, WiFi Calling often fails to register in the first place for the reasons above, so the SMS does not arrive either.

• If WiFi Calling does come up in the air: SMS to your Thai number may arrive. Text does not disturb anyone, so it is not what call bans target, but it still depends on the network letting the traffic through.
• If you use in-flight roaming: AIS says SMS works on supported aircraft, but it is billed as roaming and needs Airplane Mode off.
• An OTP sent after take-off that never reaches the phone will usually expire before landing. Request a new one after you land.
• If your bank offers in-app confirmation instead of SMS, set it up before you travel. It can work over any Wi-Fi that lets that app through.

Getting Thai SMS and OTP codes while abroad

What does WiFi Calling on a plane cost?

If it works at all, there are two costs. The first is the airline's Wi-Fi pass; some airlines give it free by cabin class or membership tier, others sell passes. The second is your Thai carrier's call charge under the WiFi Calling terms of your package. How a Thai carrier bills depends on the package, so check the carrier's official page. In-flight roaming is billed under a roaming package or roaming rates, which is a separate matter.

On data volume: a WiFi Calling voice call uses little data. General sources put it at roughly 0.5 to 1 MB per minute (an estimate, not an official figure). On aircraft Wi-Fi sold by time or limited to chat, though, data volume is not the main issue. Whether the traffic gets through at all is.

Does WiFi Calling cost money? How it is billed

What phone etiquette should you follow on a plane?

The main reason airlines ban calls is noise in a closed, crowded cabin where passengers sit side by side for hours and cannot move away. Even British Airways, which allows calls, asks you to use headphones and keep your voice low. These habits work on any flight.

• Always follow crew instructions. If the crew asks you to end a call or switch a device off, do it straight away.
• Use chat instead of calls. A text, or a short voice note the other person plays later, beats a live conversation.
• Silence ringtones and notification sounds; set the phone to silent or vibrate.
• If the airline allows calls, use headphones, speak quietly, keep it short, and avoid rest periods and night flights.
• Do not run video calls or play audio out loud without headphones.
• During take-off and landing, follow the airline's announcements about electronic devices.

How do you use WiFi Calling after landing if you have a travel data eSIM?

Once you land, the challenge shifts from airline rules to where your internet comes from. esimonline travel eSIMs are data-only, with no phone number, so WiFi Calling still runs on your Thai number (AIS, True or dtac). The most direct approach is to use WiFi Calling on real Wi-Fi, such as your hotel or a café, and use the eSIM for data while you are out.

In a dual-SIM phone, whether your Thai line's WiFi Calling can ride on the other line's (the travel eSIM's) data depends on the phone model and the carrier's settings; it does not work on every phone. Do not assume it will. Test it first, and keep data roaming off on the Thai SIM so you are not charged for roaming.

Using WiFi Calling abroad and calling Thailand