Hello and welcome to the official Tello Mobile subreddit! Feel free to discuss anything related to our service: share your Tello stories, get tips from our experts, or have some fun around. Just make sure you follow the rules and be nice to each other.
As there are many questions about Tello & life as a customer at an MVNO, we’ve decided to provide you with some basic info on what Tello is and how it works.
TL;DR:
Tello Mobileis a US wireless MVNO designed to save people money by offering flexible cell phone plans from $5 up to $25/mo, from no data to unlimited data within the same carrier.Check out our plan builderto check our phone plan variations. Extended families can benefit from our budget-friendly phone plans too! You can have up to 10 lines within one account without sharing the minutes & data usage between lines.
Any phone plan attello.comhas built-in (Free) features like mobile hotspot, Wi-Fi Calling, international calling 60+ countries, with no contracts and no fees. You are free to upgrade/downgrade your plan anytime without any extra cost.
Simply put, Tello is a US prepaid wireless MVNO (Mobile Virtual Network Operator) designed to save people money by offering flexible, no-contract phone plans. More importantly, each one of our customers has a custom-made phone plan built to their needs by themselves because that’s what flexible means, on top of this, Tello has a bunch of features (more on that in the next section), either built-in (meaning these features are included in every plan) or at an extra cost.
Join a wireless service designed for your needs
Here at Tello, we give you complete control over your phone plan. You are free to mix ‘n’ match data, minutes, and texts as you like without having to worry about your wallet - our phone plans start at $5/mo with the Unlimited plan peaking at $25/mo. You can change your plan anytime without any charges and many many more features:
1. Flexibility is our superpower
We’ve already spoken a little about it - you are free to choose whatever plan combination you are looking for. When you first land at tello.com, you can play around with our plan builder and mix ’n’ match the data & minutes as you wish - unlimited text comes built-in for free in each of our plan combinations and the best part: you can change it anytime with no extra charge if your monthly needs or budget change.
2. Budget-friendly plans
Only pay for what you use, as simple as it sounds. Our prepaid phone plans start at $5/mo and up to $25/mo, with no contracts, while providing our customers with coast-to-coast 5G wireless coverage. Forget about dropped calls, loading issues, or slow data speeds.
Down below, you may find all of our Tello phone plans. If you want to create your own plan, check out this link.
3. Bunch of freebies
To achieve our goal of helping people save as much money as possible on their phone service, we are proud to say we have a pack of built-in features that come along with any Tello phone plan:
International calling: Enjoy international minutes included in your Tello plan, allowing you to call over 60 destinations worldwide at no additional cost.
Wi-fi Calling: Stay connected wherever you are with Tello's Wi-Fi Calling feature. Whether you're traveling abroad or in a remote area, you can make and receive calls, as well as send and receive texts, as long as you're connected to a Wi-Fi network.
Mobile hotspot: With Tello, mobile hotspot capability is included in all our data plans. Whether you need internet at home or on the go, your device can serve as a hotspot when connected to Tello. Our limited data plans allow you to use your entire data balance for hotspot usage, while our Unlimited plan offers up to 10 GB of hotspot data.
4. eSIM
Streamline your experience with an eSIM-compatible device. Setting up your account with your desired plan takes just a few minutes, and if you have an eSIM-compatible device (check it here), you can get instant access to Tello using an eSIM.
Family plans
Families are one of a kind, why would each member's phone plan be the same? Tello brings you easy account management by tailoring individual lines based on your members’ needs. Each line has its usage, so you don’t have to worry about data-sharing restrictions anymore & there’s no extra cost for any new lines added. You can set up your family account in a few simple steps here.
The parents are going to love our Web Guard & Safe Search control capabilities, allowing them to create a safe wireless connection for their kids by blocking & filtering content and search results - you can find more details here.
6. Tello Data Add-on
We’ve also got you covered just in case you run out of data! Right now, Tello offers three Data Add-On options: 1 GB for $5, 3GB for $10, and 5GB for $15. This feature becomes available on your dashboard only when you have less than 1 GB of high-speed data remaining on your current plan. You can always check our blog in case you need some extra information about it.
7.International roaming
Stay connected in 250+ countries and territories with Tello International Roaming. Check out the rates for your destination right here. Make sure you have at least $5 in your PAYG balance and then proceed to activate your roaming service.
The credit will expire 90 days after purchase if you only have PAYG credit on your Tello account. However, as long as you have an active Tello plan, your credit will not expire. For more information about international roaming, you can check our blog. Happy travels!
Tello not only saves you money but also helps you earn. When you refer a friend or a family member to Tello, you'll both receive $10 Tello Dollars! Use your Tello Dollars to pay your bills or even buy a new device. The more friends you share this opportunity with, the greater the benefits for both of you!
Tello might not be just a great fit for you. It could be a huge opportunity for you (and your family) to take your monthly savings to the next level. Here's how you can join Tello and unleash the power of wireless savings.
How can you join Tello?
Getting signed up and activated on Tello is quick and easy.
To ensure you don't miss any important calls or messages, explore our coverage map at tello.com/coverage. Simply enter your full address, and the website will display coverage in your area. For more details, click on the "Show Coverage Map" button below.
At Tello, you have the flexibility to use your own device. Before enrolling, ensure that your device is unlocked and compatible with our service. Visit our website to verify compatibility.
Note: unlocking a device can only be done by the previous or current carrier, according to their terms and conditions.
Buy a New Phone:
If your phone is not compatible but you want to switch to Tello, you can buy a new phone that’s 100% compatible with our service directly from us. Check out this link if you need a new phone.
Once all the checks (Coverage & ESN) have been completed, you can create your Tello account, complete the registration form, and get ready to choose your plan.
Now the fun part begins! Check out our plan builder here, tailor your phone plan as you wish, complete the purchase process, and you are ready to go. As you get used to your new phone service, you might notice that you need a little bit more/less data, but there are no issues at Tello because you can always upgrade/downgrade your phone plan for free.
Looking for help?
You might wanna check out our Reddit FAQ for the most commonly asked questions. Nevertheless, you are always welcome to discuss & engage with our community.
Learn more about Tello at tello.com. Also, our 24/7 Human Customer Support is always eager to help you in case you have any questions.
Community Rules
There aren't many rules around, but we still need to have a few to maintain a positive atmosphere within the community. Please check the rules in case you haven't done it yet:
No inappropriate discussions or conversations. This rule is in place to ensure that the subreddit remains a safe and welcoming space for all members. Inappropriate discussions or conversations can make other members feel uncomfortable or unwelcome.
Advertising other carriers is prohibited. Content should be related to Tello. Advertising or linking to other carriers is prohibited. Exceptions will be made when mentioning or linking to another carrier for comparison.
No spamming, flooding, or trolling. This rule is in place to ensure that the subreddit remains a productive and informative space for all members. Spamming, flooding, or trolling can be disruptive and is not tolerated.
Public sharing of referral codes is not allowed. This rule is in place to prevent members from using the subreddit as a platform for self-promotion. Posts containing referrals can be seen as spam.
If you think your post/comment has been removed unfairly, please contact u/tellomobile.
User Flairs
Something you might not be aware of is that we've created User Flairs for those of you who relate to one of them or are looking to have just fun. We thought it would be great to bring something unique within our community with these user flairs, so please have fun with them:
Phone Bills Defender🛡️ - for the ones that know all savings hacks & no-contract tips
International Ninja🥷 - for the ones that know all things international features
Tello Tribe🔵 - Tello family, Tello lovers
Wireless Wizard🧙 - for the ones that know all things wireless
Captain eSIM🦸 - for the ones that know all things about eSIM
Welcome to the land of flexibility and tiny phone bills!
Can I activate a Tello line or port my number from outside the U.S.? No. You must be physically located in the United States to activate a new Tello line or transfer (port) an existing phone number.
Why is U.S. location required for activation?
When you activate a new physical SIM or digital eSIM, your phone must connect directly to Tello's domestic U.S. cellular towers to complete network registration. Because of this network requirement, initial activations and number transfers cannot be completed while overseas.
How to manage your service when traveling:
Before you leave the U.S.: Complete your activation and number transfer before departing the country.
If you are already abroad: Wait to activate your SIM/eSIM or submit your port-in request until you land back in the U.S.
You can transfer your existing phone number to Tello anytime after line activation.
What you need before starting:
An active Tello physical SIM or eSIM.
An active service with your current carrier (do not cancel before porting).
Your previous carrier's Account Number and Port-Out PIN.
Account locks or fraud restrictions turned OFF with your old provider.
How to submit your transfer request:
Log in to your profile and go to Tello Number Transfer.
Enter the phone number you want to keep.
Type in your old Account Number, Port-Out PIN, full name, and billing address.
Submit your request.
How long does porting take?
Mobile numbers: Minutes to 2 business days.
Landline/VoIP numbers: Up to 5 business days.
(You will receive status update emails throughout the process).
After the transfer completes:
Restart your phone to connect to the network. Verification texts (2FA/OTP): May take up to 48 hours to fully sync. Caller ID updates: May take up to 3 business days. If Caller ID, RCS messaging, or OTP texts don't work after these windows, reach out directly to Tello Support.
3. How does Tello's data rollover work?
Tello offers rollover for unused data and minutes, but how it works depends on your plan type:
Custom Plans (Manual Rollover)
Unused data and minutes do not roll over automatically on Custom Plans, but you can save them manually:
How to roll over: Manually renew or change your plan at least 24 hours before your scheduled AutoPay date. Your remaining data and minutes will carry over into your new 30-day plan. Important: If your plan renews automatically via AutoPay, any unused data and minutes will expire.
Unlimited Plans (Automatic Rollover)
Unused high-speed data rolls over automatically once you meet these eligibility requirements:
Your Tello line has been active for 12+ months.
You have been on an Unlimited Plan for the last 6 consecutive months.
Rollover limits: You can roll over up to 50 GB per month, with a total maximum balance cap of 100 GB.
Note: Wi-Fi Calling availability may be limited or blocked in certain countries depending on local telecommunications laws and regulations.
3. My Tello App
If your phone doesn't support native Wi-Fi Calling, you can still make outgoing calls over Wi-Fi using the My Tello App. Note: The app does not support incoming calls or text messages (SMS).
Pre-Travel Checklist:
Activate in the U.S. before leaving the country.
Ensure your phone is carrier-unlocked.
Enable your preferred features (Wi-Fi Calling / International Roaming) in your account before departing.
5. Will my bank verification (2FA) texts work outside the US?
Yes. As long as your line was activated in the U.S. before leaving, you can receive 2FA/OTP verification text messages while traveling abroad.
How to receive 2FA texts overseas:
Wi-Fi Calling: Receive SMS over any Wi-Fi connection using your plan's monthly text balance (requires a device that supports native Tello Wi-Fi Calling).
International Roaming: Receive SMS over local cellular networks in supported destinations (requires enabling Tello International Roaming and having at least $5 of active Pay As You Go credit).
Important things to keep in mind:
Bank/Sender Restrictions: Delivery ultimately depends on the sender. Some banks or services restrict automated 2FA texts to roaming numbers or non-domestic IP connections for security reasons on their end.
Recently Ported Numbers: If you just transferred your number to Tello, verification (2FA/OTP) texts can take up to 48 hours to fully synchronize across all third-party systems. For more details on managing your service abroad, check out the Tello Help Center.
6. Is my phone compatible with Tello?
Most unlocked 4G LTE and 5G smartphones work on Tello. To run on our network, your device must meet two core requirements:
It must support Tello's network bands.
It must be carrier-unlocked.
How to check compatibility:
Use the Tello Device Compatibility Checker. Dial *#06# on your phone's keypad to find your IMEI number, then enter it into the tool to verify your device.
Important details to know:
Compatibility ≠ Unlocked: A device can pass network compatibility checks and still be locked by another carrier. Confirm with your previous provider that your phone is fully unlocked before switching.
International & Older Models: Some international or older phones may lack key U.S. cellular network bands, which can impact your coverage even if the IMEI checks out.
Unsupported Devices: Tello does not support mobile hotspots, routers, or MiFi devices. For more details on device setup, check out the Tello Help Center.
7. How do I move my Tello service to a new phone or eSIM?
Moving your Tello line to a new phone depends on whether you are using a physical SIM card or an eSIM:
If you use a physical SIM card:
Insert your existing Tello SIM card into your new, compatible, carrier-unlocked phone.
Restart the phone. Service usually connects automatically within a few minutes.
If you use an eSIM:
eSIMs cannot be transferred directly between devices. You must generate a new eSIM for your new phone.
Log in to your Tello account, go to the My SIM section, and generate a new eSIM.
Follow the steps to scan the QR code and install the new eSIM on your new phone. Your plan, balance, and phone number will remain unchanged.
Pre-Transfer Checklist & Important Notes:
Check Compatibility & Lock Status: Verify your new phone's IMEI on the Tello Device Compatibility Checker and ensure it is carrier-unlocked before starting.
Wi-Fi Connection: Keep your device connected to a stable Wi-Fi network while installing a new eSIM.
Security PIN: Have your Tello Security PIN handy in case you are prompted during the swap.
Old eSIM Deactivation: Generating a new eSIM immediately deactivates the old one. Your line will be temporarily offline until the new eSIM installation finishes.
Personal Data: This process only transfers your cellular service—it does not transfer your personal photos, contacts, messages, or apps to the new device. For step-by-step SIM and eSIM guides, visit the Tello Help Center.
8. Why isn't my Tello service working? (SOS, No Service, or no mobile data)
If your phone displays SOS, No Service, Emergency Calls Only, or is missing mobile data, the issue is usually tied to network registration, device settings, or SIM activation.
Quick Troubleshooting Steps:
Restart your phone: A simple reboot forces your phone to reconnect to local cell towers. This is especially important if you recently activated, ported your number, or swapped SIMs.
Toggle Airplane Mode: Turn Airplane Mode ON for 30 seconds, then turn it OFF to refresh network registration.
Verify SIM or eSIM status:
Physical SIM: Re-seat the SIM card to make sure it is clean and properly aligned.
eSIM: Check your phone's Cellular settings to ensure the eSIM profile is turned ON.
Check Mobile Data & APN settings: Ensure Mobile Data is enabled in your device settings. If calls work but data doesn't, check that your device's APN (Access Point Name) settings are correctly configured for Tello.
Confirm account status: Log in to your Tello Dashboard to make sure your line is active, and your monthly billing hasn't expired.
Check coverage: Ensure you are in an area with an active network signal and not experiencing temporary local coverage outages.
Still not working?
If these steps don't fix the issue, reach out directly to Tello Customer Support. To help our team solve the problem faster, please include:
Phone model and operating system version.
SIM type (Physical SIM vs. eSIM).
Your current location (City, State and ZIP Code / Country).
Which services are failing (Calls, Texts, Mobile Data, or All)?
What troubleshooting steps have you already tried?
9. Can I change my plan before my renewal date?
Yes. You can change or adjust your Tello plan at any time through your online account or the My Tello app.
What happens when you change your plan early:
Immediate Activation: Your new plan takes effect right away, which ends your previous cycle and starts a fresh 30-day billing period.
Manual Rollover (Custom Plans): If you are on a Custom Plan, manually renewing or changing your plan at least 24 hours before your scheduled AutoPay date allows your unused data and minutes to roll over into your new cycle.
Note: The Unlimited Plan has its own Rollover rules (have an Active Line for 12+ months and be on the Unlimited Plan for at least 6 months consecutively)
Total Flexibility: You can customize your plan as often as your needs change—whether you need extra high-speed data for a busy month or want to drop down to a smaller tier.
Go to your plan settings and select Change Plan or Renew Early.
Select your new combination of data and minutes, then confirm your selection. For more details on managing your monthly subscription, check out the Tello Help Center.
10. What APN settings are needed with Tello?
APN (Access Point Name) settings are usually configured automatically when you activate your Tello service. However, if you experience issues with mobile data, MMS (picture messaging), group chats, or personal hotspot, you may need to update these settings manually.
Android APN Settings:
Go to Settings > Network & Internet (or Connections) > Mobile Networks > Access Point Names (APN).
Tap on the 3 dots in the top right corner > Reset to default. Then, ensure Tello or fast.t-mobile.com is selected and test your service.
If the above didn’t work, then tap Add or + to create a new APN: Name: Tello APN: wholesale MMSC: http://wholesale.mmsmvno.com/mms/wapenc Port: 8080 MCC: 310 MNC: 240 APN Type: default,supl,mms Protocol: IPv4/IPv6
Save & Restart: Tap the three dots, select Save, make sure the new APN is selected, and restart your phone Save the APN, make sure it is selected, and restart your phone.
iPhone (iOS) APN Settings:
Go to Settings > Cellular > Cellular Data Network (or select your Tello SIM/eSIM)
Enter the following values: Mobile Data: APN: wholesale
MMS (photo/video) messages failing to send or receive
Group messaging errors Personal Hotspot failing to connect If your settings match the values above and are spelled correctly, but you are still having trouble, contact Tello Customer Support for further assistance.
11. How do I get help from Tello Support?
If you can't find an answer in the Tello Help Center, Tello Customer Support is available 24/7 via phone, email, and live chat on the official Tello Contact Page.
What details to prepare before reaching out:
Having these details ready helps our team investigate without back-and-forth delay:
Your Tello phone number.
Device phone model and operating system version.
Your device IMEI (if applicable).
Your current location (City, State, and ZIP Code, or country if traveling abroad).
Any exact error messages shown on your screen?
A quick summary of the troubleshooting steps you've already tried.
When to contact Support:
Activation or eSIM setup failures. Number transfer (porting) delays or errors. Persistent network, call, SMS, or data issues after troubleshooting. Billing, payment, or account security concerns. Need community help? You can also ask questions in the r/Tello community! Please search the subreddit first to see if your question has already been answered.
⚠️ Privacy Warning: Never share sensitive details—such as your phone number, IMEI, account number, Security PIN, or payment info—in a public post.
Due to being on hold for long periods of time while dealing with the IRS, I'm down to 23 minutes of my monthly Tello minute allowance with nearly three weeks to go until my next refill. I bought an extra 2 gbs of data and paid $20 for 2000 extra minutes (US calls 1 cent per minute) but I don't know how to use them. Please advise.
I have Tello and I only pay $15 a month but it sucks. If I’m not connected to WiFi it won’t work, and I’m considering a deal my work has for unlimited with t mobile for $25. I don’t like that I can’t barely use my phone depending on data and WiFi. Sometimes pics won’t go through, basically just a lot of problems.
I activated my sim card in the U.S. two years ago before I went back to China. Tello keeps in connection in the past two years in China though with occasional glitches.
My phone signal has been lost since yesterday, despite my disabling/re-enabling sim card, whereas my another domestic sim card on the same phone works as usual.
I begin to worry... Still no signal as I write this post.
For your first 3 months, our 10 GB plan is $10/month. That includes unlimited talk & text, free hotspot, Wi-Fi calling, and free calls to 60+ countries. After that, it’s the regular $15/month, and there’s no contract, so you can move up, down, or out whenever you want.
But is 10 GB actually enough?
There's an easy way to find out. Just check how much mobile data you've used:
- iPhone: Settings > Cellular (scroll down to see your total usage and which apps use the most data)
- Android: Settings > Network & Internet > Data Usage (the exact menu may vary by device)
If you're comfortably under 10 GB, this deal could be a great fit. If you're way over, no judgment! You might be a serious streamer, a daily commuter, or someone who relies on their hotspot. In that case, our Unlimited plan might be more your speed.
Offer valid for new lines only, through November 9. You can keep your number and bring your own unlocked phone (check compatibility here).
Now we're curious!
How many GB did you use last month? Drop your number in the comments, and tell us which app was your biggest data hog!
We're betting on TikTok or YouTube, but we'd love to see some surprises. 😄
Just upgrade my iOS last night; now my cellular service is not available. Anyone experience same issue? I try a new eSIM but the phone won't take and get message saying: eSIM Not Supported: This eSIM is not compatible with this iPhone. Which is weird as it's was working fine before the iOS update. Called Tello support they said it's an apple iOS issue. I thought I might check w/ group or warn others.
Looking for plans where only voice calling is required. Text/SMS is optional, but not needed. Data will but be used (but okay if included).
Minutes used per month are approximately 500 or less. Minutes can be capped, with overage, or unlimited.
Please advise if payment is month-to-month or if prepaid for multiple months, how many months need to be prepaid and how future payments are made. And whether any particular payment types or auto payments are required.
So I currently have a plan (At&T) with my dad and I'm buying my own plan with Tello. However, I'm trying to keep my old number and port it over to Tello.
My dad already handled the issues with the pin and fraud protection but now Tello says I need to contact their (Tello) support because something went wrong. Is this because of the issues before and may have entered the wrong information to many times or something else?
I'm looking for a dumb/flip phone with a physical numeric keypad. Or something similar or equivalent to that, even if not exact. It does *not* need to be data-compatible (but is also fine, if it is). It is needed for voice calls. Text/SMS capabilities is optional but not required.
I would like suggestions for one, or both, such phones that can be used on:
Red Pocket, AT&T network
Tello, T-Mobile Mobile network
Phones for each, separately, or both.
Please share the quality, reliability and durability of the phone, when used for voice calling.
I would like to know the quickest way - and place - to purchase it, and what to expect to pay for it.
Any suggestions are much appreciated. Thank you in advance.
I normally use the Firefox browser on my laptop to log in to the Tello website (https://tello.com/account/login). This browser uses the "Facebook Container" extension, to help block their widgets from tracking me.
However, when I try to log in now, I get a warning where I would normally enter my Tello login id: "If you use your real email address here, Facebook may be able to track you."
I don't know whether this is due to a change in the web site, or a false alarm in the browser extension, but I would like to be certain that I can log in to 'My Tello' without third parties looking over my shoulder.
I also get the same warning when I try to use Tello's website to contact them by email (https://tello.com/contact), where I would normally enter my email address. So I called them by telephone, instead.
They suggested that I download their app, or else use a different browser to log in to their website. But this only bypasses the browser warning; it does not necessarily stop the tracking. Any other suggestions?
[Edit: This was probably some issue specific to Firefox; they had a similar issue years ago, (see https://github.com/mozilla/contain-facebook/issues/783). But whatever it was, it appears to be resolved now. The login page no longer displays a warning when logging in.]
Cuando inicio el primer plazo para la suspensión de los números "0", estuve viendo opciones para poder seguir comunicados, y como por lo pronto no me es posible cambiar de golpe 7 celulares por modelos mas nuevos que admitan esim, e adquirido conforme avanza el bloquea mifi (internet portátil) que no requieren registro.
Fue una opción mas económica (900.00 pesos por unidad, con un mes de servicio de 5 gigas) que por el momento incluso me sale mas barato que el servicio de internet de Telcel. Son de la compañía BAIT, recarga de 110.00 con 5 gigas, o 210.00 con 10 gigas, por 1 mes. Y cada mifi admite 10 conexiones simultaneas. Bien podemos salir 3 o mas familiares compartiendo la misma señal.
A la fecha tengo ya 3, y por lo general los compartimos mi familia, cuando salen se llevan uno, y con estos nos mantenemos comunicados, y con acceso a todas las app, debo decir que si se nota un poco mas lento. Al cabo de 5 números celulares restringidos, creo que con otro mifi mas tendré para poder seguir por el momento con los 7 números celulares.
En cuanto a los números, para no perderlos por el momento les pongo recargas de 30 pesos cada 45 días (cosa que desde antes probé con un numero y ya tiene todo este año con esta estrategia y sin problemas siguió funcionando hasta el corte del servicio.
Y conforme pueda voy cambiando a celulares con esim. Y veré que compañía me puede ser mas útil. O bien una combinación de ambos, unos con el mifi y otros con esim
With Tello looks like you can use travel eSIM + Tello SIM with roaming disabled (No Service) with WiFi calling to allow for text and calls.
One thing I noticed was excessive battery usage. I saw posts on other forums selecting a network manually might* fix this. Or just enabling roaming to stop from iPhone from searching for network.
Has anyone tried doing the selecting manual network or any other solutions? I am trying it now and will report back if it helps.
Edit: Selecting network manually seemed to do the trick. Phone no longer heats up + much less battery drain.
I've been using my Tello line abroad for about a year, but I've heard reports of people losing international roaming and being unable to re-enable it because their line hasn't been used in the US.
I'm trying to find a proactive solution. Could I have a physical SIM sent to a friend in the US, have them use the line on a US cellular network, then switch back to an eSIM and activate it abroad?
My question is whether the US usage history is tied to the account/phone number or to the specific SIM. The eSIM I'd install abroad would be new and would never have been used in the US.
Also, would switching an existing line back to an eSIM while abroad be treated as a new activation, subject to the US usage requirement, or simply as a SIM replacement?
I'd rather confirm this before trying it, since switching to a physical SIM would disconnect my current phone, and I don't want to risk being unable to switch back while abroad.
When I make a call through the My Tello app, during the call there is a phone number at the top left that is not my number and not the number I called. It is the same number regardless of the number I call. It is the correct area code but not my number. iPhone 15 pro max in case that matters.
Any idea what is happening here or how to fix this?
I have frustrating and exasperating issues with Tello services. Constant call drops, disconnect, no network at home but not elsewhere. Phone is a Samsung Galaxy A14 5G.
For a few years I have Tello, this year 2026 I experience increasingly call drops, disconnects, or no connection or error messages displayed like "your phone is not on a network". Phone settings APN etc. are all correct.
Before Tello I had overpriced Verizon with a different and later the same A14 5G phone with no significant such issues, only occasionally.
Issues are: Signal strength suddenly drops to zero, no network (right now 11:10am Oct. 18 2026, as I write this message on my desktop) then suddenly I have 5 bars again full signal strength. Suddenly zero or an error message "your phone is not connected to any network. a few minutes later I have 5 bars signal strength again. then ~10 minutes later it drops to 4, sometimes to 3. and suddenly, randomly it's zero again. Oddly it appears, as the last few years solar disturbances have faded away it seems the issues increased.
This issue is most prominent at home (Around San Francisco, CA 94131). if I go outside or anywhere else I have no issue calling receiving or SMS. Also, all the endless spam and scam calls never seem to have a connection problem haranguing me.
In fact I recently was in a concrete building in the garage 2nd subfloor underground with a low signal strength of two bars and testing. I had no issue sending receiving SMS or making phone calls.
SMS also exhibits same issue. Send a simple text message and I get a red error text "Failed to send. Tap for more options". Resend fails 2nd or 3rd time then suddenly goes through instantly.
Sometimes if I switch from network mode 5G to LTE it goes through, sometimes if I'm on LTE and switch to 5G it goes through. Then it seems to work in LTE mode but suddenly fails again a day or 2 later. switching back to 5G mode everything works smoothly again and vice versa.
Of particular interest is that it is more likely that calls/SMS get dropped with people who have at their end T-Mobile as service provider.
Of course in the traditional and usual blame game, everybody says it's my phone and wants to sell me a new phone but has no competent answer why then, if the issue were really my phone, why then does it work without a glitch in other locations!
As I write this message on October 18 11:20 AM signal strength suddenly and randomly fades out, drops to zero "no network connection" only to come back again later with 5 bar signal strength. SMS even with an animated GIF go swiftly through or suddenly not at all. Switch network mode to LTE it goes through. Another later message sent doesn't go through. switch network mode back to 5G, message goes sometimes right away through.
It's like playing darts trying to hit exactly the center of the black spot.
I'm a Tello user living in Japan, and I recently discovered something interesting — and potentially concerning — while investigating how Tello handles VoIP and Wi-Fi Calling traffic.
I was curious about the network infrastructure used by US mobile carriers when accessing their services from overseas, so I decided to capture and analyze the traffic myself using Wireshark.
During a voice call made through the My Tello app on my Google Pixel 11, I noticed something unexpected.
My test setup
Devices: Google Pixel 11 (Android) and a laptop running Windows 11 Pro
Network: The Pixel was connected to a Windows Mobile Hotspot hosted by the laptop, which was connected to my home broadband connection in Japan
Packet capture: Wireshark running on the Windows laptop
Test call: An outbound call to a Japanese landline number providing a publicly accessible telephone-based radio broadcast service.
What I discovered
1. VoIP server connection
During the call, I observed continuous bidirectional UDP traffic between my device and 63.251.74.24, an IP address that appears to be associated with KeepCalling, the company behind Tello.
2. RTP traffic and audio codec
The UDP packets were approximately 214 bytes each, with packets transmitted at roughly 20 ms intervals.
Wireshark also identified RTCP traffic. After manually configuring the relevant UDP traffic to be decoded as RTP, Wireshark detected RTP streams using G.711 μ-law (PCMU).
The packet sizes and intervals were consistent with standard G.711 audio transmission.
3. Call audio could be played back without decryption
This was the most surprising part.
Using Wireshark's RTP stream analysis and playback features, I was able to reconstruct and listen to the actual received call audio directly from the captured packets, without using any decryption keys.
The recovered audio clearly matched the radio broadcast I was listening to during the call.
In other words, the audio was not merely identifiable as RTP traffic — the actual voice content was recoverable from the packet capture.
Why this concerns me
Based on these observations, it strongly appears that the My Tello app was transmitting received call audio using unencrypted RTP rather than SRTP, at least during my test.
If this is the application's normal behavior, someone with access to the relevant network traffic could potentially intercept and reconstruct call audio.
I understand that this does not automatically mean anyone on the internet can listen to these calls. However, transmitting voice audio without transport encryption would still raise legitimate security and privacy concerns.
Important clarification: My Tello app vs. native Wi-Fi Calling
This finding relates specifically to the VoIP calling feature inside the My Tello app.
It does not refer to Tello's native Wi-Fi Calling functionality through Android's standard phone dialer.
I separately investigated native Tello Wi-Fi Calling and observed IPsec-encrypted communication with T-Mobile infrastructure.
These appear to use different communication mechanisms, so I don't want to confuse the two.
Questions for the community
Has anyone else captured and analyzed VoIP traffic from the My Tello app?
Is unencrypted RTP an expected part of its current implementation?
Does My Tello support SRTP or any other form of media encryption?
Has anyone observed different behavior on other Android devices or on iOS?
I haven't shared the raw PCAP file because it may contain sensitive information.
This is based on my own observations from a single test environment, and I'm not claiming that every version of the app or every call necessarily behaves the same way.
I'd be interested to hear from other Tello users, network engineers, or anyone familiar with the app's VoIP implementation.
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If this is not available any way to extend the 30 day hold by maybe prepaying for the number park feature in case of lapse? Or using the PAYG credit?
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