I am staying in the US for 3 months, and I want to have a cheapest possible mobile data plan for it. I think it makes no sense and is a waste of resources to buy a new phone just for that phone, so that solution I'd very much avoid.

What I've tried so far: my German SIM works and connects readily to T-Mobile network. This makes me assume that compatibility of local LTE bands and the ones my phone supports is not an issue. Yet, I have no connectivity with the two SIMs I tried.

Specifically, I tried with US Mobile and LycaMobile. When experiencing problems with the first, I specifically checked on LycaMobile's compatibility checker if my phone is compatible, which the site tells me it is. I also had no connection with LycaMobile, texted their customer support, had it work for a day or so, and then it stopped working again.

The facts that it worked for a while, that LycaMobile uses, afaik, T-Mobile network, and that my phone connects effortlessly with T-Mobile when using roaming make me assume that there should be a solution without buying a new phone.

But: how to I either get my phone work with LycaMobile, or any other carrier?

The phone is a SIM-unlocked Samsung Galaxy A5 SM-A520F, the TAC is 35260209.

PS: I don't care if I likely only get 3G rather than LTE, if I can get that reliably, at least.

  • 5
    You know your phone is functional with T-Mobile. Why haven't you gotten a T-Mobile SIM and tried it?
    – Makyen
    Commented Oct 16, 2022 at 4:12
  • Because your phone worked for a while with LycaMobile, it seems like your best option is to simply contact their support and stick with the support staff until the issue is resolved. There probably is just a reboot or two in order, etc.
    – travelgasm
    Commented Oct 16, 2022 at 6:25
  • 1
    You get what you pay for. LycaMobile has a strong history of going bankrupt. See techbook.de/connectivity/lycamobile-insolvenz-mobilfunk-1 and seems rather sketchy
    – Hilmar
    Commented Oct 16, 2022 at 7:04
  • While it may not answer your question directly, I find Prepaid SIM Wiki to be quite useful in all countries I visit.
    – yeputons
    Commented Oct 16, 2022 at 11:45
  • You haven't said what you need the phone for. If it is for making phone calls, just buy a cheap phone. Commented Oct 16, 2022 at 17:10

3 Answers 3


The two keywords you're after are "pay-as-you-go" and "bring your own device".

The clerks at any retail shop of any cellular carrier will be well-acquainted with both terms. Yours is a common request.

They're going to set you up right in the shop and test it on the spot. Either it'll work and you're in business, or it won't and they'll send you off with apologies or figure out a phone for you.

The cost of maintaining obsolete cellular network equipment is staggering. Every 3G tower kept alive soaks up a lot of maintenance cost, tower rental, and precious radio spectrum. That is why carriers are pushing people really hard to the newest networks, and why they may not let you enter the network with an older phone.

The top carriers (Verizon and AT&T) have more interest in supporting legacy systems, because they have well-heeled corporate customers with embedded systems - power companies with pole-top monitors, or railroads with transceivers in wayside boxes and locomotives. Those things are too costly to re-engineer and replace for every cellular generation. AT&T and Verizon are willing to maintain legacy networks for those customers.

Whereas the "value" carriers (the RyanAir of the spectrum) keep it simply by only supporting 1 or 2 generations. Reduces spectrum cost, reduces tower rental, reduces engineering costs. T-Mobile found it was more profitable to give me a decent 5G phone than to continue standing up a 3G network. They are cannibalizing their 3G and 4G spectrum and towers to expand their 5G.

Thus your conflict. Your expectations on price are set by the discount carriers, yet your old device requires support only the Tier 1 carriers offer.

I think now is the time to think about the value of your time.

I said above "walk into a shop". That's because you have a "corner case" and the web sites are just not set up to deal with that.

And if you need to buy a phone, consider a used one off Craigslist, Facebook Marketplace, eBay etc.

  • 4
    +1 I agree with most of this, except I would add that of the larger carriers, a Verizon SIM is less likely to work in a non US device than a SIM from of the other carriers. They'll support older US released devices, but more often than not they won't support even newer devices that aren't the same as the US model. Their network probably will (eg connect with your home SIM), but their SIM cards won't .
    – Midavalo
    Commented Oct 15, 2022 at 21:54
  • Very good advice here! I would take it one step further with the specificity and tell the OP to go to a retail shop of specifically either Boost or Cricket. Not sure if that would be appropriate though. Commented Oct 16, 2022 at 8:40
  • yes, Verizon and sprint use whitelists of IMEI numbers and foreign phones are likely to be rejected. T- Mobile does not and maybe att does not
    – Mike M
    Commented Oct 16, 2022 at 16:48

You need a new phone because yours does not support VoLTE

The problem you are experiencing is that even though your phone is LTE, none of the major US carriers list it as supporting Voice over LTE (VoLTE). Without VoLTE, a phone has to drop down to 3G or 2G networks to place a voice call, which have now largely been shut down in the US.

US carriers are using a VoLTE whitelist because of strict regulations and liability concerning emergency calling (911/112). The US Government also requires carriers use a complex GPS/cell tower location system to determine the location of phones making emergency calls (WE911), and that requires specific testing.

As a result, while carriers may allow roaming traffic for now, they require a whitelisted IMEI to activate on their network. Further phones must support VoLTE to work, even if the user desires data-only use, due to the possibility that somebody will attempt to make a 911 call in an emergency.

The status of the 3 US nationwide carriers are:

  • AT&T officially shut down all pre-LTE 2G and 3G networks in February 2022, so it is impossible to place a call without VoLTE. Here is the AT&T whitelist.

  • T-Mobile officially shut down all pre-LTE networks as of July 1, 2022. T-Mobile still has a 2G network operational, but it is intended for M2M devices only. T-Mobile IMEI check

  • Verizon is actively shutting down their pre-LTE 2G/3G networks, to be completed December 31, 2022. Verizon's pre-LTE network is CDMA-based and the vast majority of non-Verizon or foreign phones do not support it (with the exception of certain iPhones). Verizon IMEI check

All prepaid MVNOs must follow the rules of their base network.

  • 1
    Thank you. That explains the observations quite well. I was about to ask what if I want data only, but you covered that. But: I saw there are plans for tablets and other devices that are data only. Do they have a greater chance to work?
    – Bubaya
    Commented Oct 18, 2022 at 18:07
  • @Bubaya I read for AT&T that they specifically distinguish, via the IMEI/TAC, between data-only devices like tablets and hotspots, which are permitted on the network without VoLTE, and phones, which are blocked without VoLTE approval. I believe the other carriers are similar.
    – user71659
    Commented Oct 18, 2022 at 19:23


Mint Mobile , mintmobile.com ,
is the lowest price option that I know of which is on T-Mobile networks.
I also went to T-Mobile for my foreign Samsung in the US.
Verizon and Sprint, iirc, use whitelists of IMEI numbers sold in the US, and likely will reject your foreign phone.

When Mint got going it was an easy choice since I don't use so much data.

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