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.

Thanks!

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.

Also, how reliabel is SMS outside of cell coverage area (wifi internet connection only) ?

Thank you very much!

Hi everyone,

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.

Thanks for reading!

I’ve been very happy with Tello over the last 6 months. Great for OTPs while living in another country. The $5 plan is ideal for keeping the US number active.

Referral code in my profile. Click on my profile for a referral link. Both of us will get $10.

It looks like there isn’t a way to add a backup payment option in case primary billing method fails due to expiration? Am I missing something or is there no way to keep a backup to keep the monthly plan funded?

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?

Hi everyone! 👋

I need some help activating my Tello eSIM. I’m currently living outside the USA, and the eSIM needs to be activated in the United States first.

If anyone is currently in the USA and can help me activate it and enable international roaming, I would really appreciate it.

Thank you so much for your help! 🙏🇺🇸

I bought an eSIM for later setup / activation.

As my past experiences was the 30-day cycle doesn't start until you activate the SIM.

That's not the case with Tello. When you purchase an eSIM at Tello, the cycle starts immediately.

That's very unusually unique.

I've been using Tello with a Google Pixel. Right from the start, voicemails on my Tello line would show up properly in the default Voicemail tab, and I could play the messages from within there without having to dial in. Sometime within the last few months that stopped working, and I have to dial the Tello voicemail number and enter my password to retrieve my voicemails. I have no transcripts or ways to play them without dialing in.

I have tried going to the Phone app's settings and voicemail and there's no "Visual voicemail" option at all. It's just gone.

I tried deleting all storage and cache for the phone app, with no impact. Help? What am I missing?

Update: discussed with TELLO support agents and we were able to resolve it with the new eSIM. Everything works now, no further issues. I am happy and relieved; thank you all who contributed and have a wonderful night.

iPhone 17

I tried adding images but for some reason it won’t let me.

Tello customer since August 2026 in USA

Currently in Thailand on long work trip

Added local data esim-data works fine
Doing this changed inadvertently voice to “business”

I changed the voice back to “Tello”

No voice or text, no bars, “sim not provisioned, network says no carrier, carrier says “carrier72” APN says wholesale, activate wifi calling says to contact carrier

I requested new eSIM but paused there because I don’t want to mess it up any further

Any idea how badly I’ve messed this up and any tips to get back in track?

I’ve emailed support through their online form, but haven’t received a reply yet.

help!🙏🥺

I am being bombarded everyday with political texts. I block and report, but those last several days forwarding to 7726. I don’t even get a response. Is spam reporting not working anymore?

I have been reading about all these unlocked phones and I can not find one that is compatible with Tello.

I found this BLU G-75 one in BestBuy but still says Compatible "AT&T, Verizon, T-Mobile, Metro by T-Mobile, Cricket, Mint Mobile, Total Wireless, Visible, Tracfone"

I would appreciate any help

I'm in France and I don't seem to have internet access when away from wifi. I've turned on international roaming, have a pay as you go balance and 2 gig of data left on my monthly plan. Any suggestions?

Hey Tello Tribe!

You share feedback here, and we do our best to turn it into action. A couple of recent updates came directly from you:

- Free roaming in Europe: Many of you travel to Europe, so we launched free roaming there this summer. You asked us to keep it going, so we extended it.

- More time to keep your number: You wanted a longer grace period if your plan isn’t renewed. We heard you! You now have 30 days instead of 12 to take action before your number expires.

Keeping numbers active for longer means more work on our end, but your feedback made it clear this was worth doing.

So keep the suggestions, questions, and honest feedback coming. We’re listening, and this community genuinely helps shape what we do next.

I have a phone with Tello that gets 4 bars of LTE or “SOS”, when the t-satellite eSIM gets 5GSA and hundreds of mbps..

hey, I'm in India and have a US number on Visible that I want to keep, mainly for bank/account OTPs and iMessage with friends. I'm using an unlocked iPhone 14 Pro and want to switch to something cheaper.

my cousin is in the US and can activate an extra line on his phone. I've been looking at Tello, but their current help page says activation and port-in need to happen in the US.

has anyone recently had a US friend/family member activate a line and port their existing number, then generated a replacement eSIM to use on their own iPhone in India? did bank OTPs and iMessage work after the move, and did support confirm the process was allowed?

also open to another carrier. my next Visible charge is Oct 14, so I'm trying to sort this before then. what's the safest way to switch without losing access to my number or bank OTPs? would really appreciate recent first-hand experiences, including anything that failed.

I am 39, and I plan to move next year. Do you think Tello will be with us for the next 30-40-50 years? I currently have Google Fi and want to switch for the savings, but if Tello closes, I will not be able to port my number back to Google Fi without going back to the USA and activating my card there. I am just thinking long-term here.

Edit - thanks all for your thoughts. Who knows - maybe Starink will be the next phone provider, it just makes sense.

No matter what I do, I cannot get call forwarding to work at all. I have been attempting to enable it, and every time, I receive the following error message: "Network or SIM card error".

I've tried reseating the SIM card. I've tried removing the SIM card and clearing the phone app's settings. I have tried resetting the network. I have tried using the short codes. Nothing is working and I am at my wits end!

The phone I am attempting to set call forwarding up on is a Google Pixel 6. However, I also tried a different phone on my account just to see if it would work for that phone. Again, I received the same error message. That phone was a Pixel 9.

What am I missing or doing wrong? Please help!

Edit: The Pixel 6 is using a new physical SIM card. The Pixel 9 is using an eSIM.

As title says -- I'm currently abroad. I have an iPhone 15 pro and may upgrade soon to an 18 pro. I know that I will be able to set up wifi call/text according to other threads in this sub, but it's unclear if mms can ever be routed through wifi or my local sim's data. Has anyone been able to get sms/rcs/mms working over wifi or another sim's data? Thanks.

If needed I can wait until I am back (just a few weeks). But it would be nice to get off my expensive US t-mobile plan.

Tello didn't have RCS E2EE several months ago when I had its service, but I'd consider returning if it has since added it -- does Tello have RCS E2EE now? If not, does it have a timeline for activating it?

Data point for those who care:

Tello roams on Bouygues in France

One of the few countries without a Telekom subsidiary in it so was curious who they partner with. Does T-Mobile Postpaid roam on the same network here?

I'm living outside the US. Tello has been working fine until the last month or so. When I am not connected to WiFi, I lose service for Tello. This was happening sporadically, but now is happening all the time. I have a local (Danish) number that Tello has seemingly been working fine with for backup calling until now. I've never had any pay as you go funds. Calls and texts with Tello work fine when connected to WiFi

What should I try first to troubleshoot?

My tello line was off and i was using Wifi only . i logged into my Tello account online and noticed that there were 7 text messages logged. I never received the messages on my iphone.

Is there a way i can view the Meta data/details associated with these texts.?

I’m going to be traveling to Taiwan for one week. I have $20 PAYGO credit.
I’m trying to decide if I should use their roaming or buy an eSIM for my one week in Taiwan.

My partner will likely get an eSIM because they use Google Maps and AI a lot while we are traveling. My use will be recreational or if I get lost. Maybe use Line and Instagram.

I can wait until we get back to the hotel to upload any photos.

Thoughts or suggestions?