I travel to US every year (sometimes once every 2 years). Every time that I arrive in a country, I buy a cheap prepaid SIM card. The problem is that all these cheap SIMs have a short inactive life, due to their pay-as-you-go nature. For example, most of them will die after 3 months of inactivity, and it is almost impossible to reactivate them.

Is it possible to buy a SIM, which work for a long time regardless of its activity? I wish to have a permanent mobile number in the US. I can get US numbers via Google voice and such, but then I need to buy a separate SIM card and set up forwarding and such, which can get complicated. (If this is the best option, I need a step by step explanation of how to make it work).

I'm looking for either a prepaid solution (with a 24-month lifespan) or a postpaid solution that I can activate to an expensive plan while there, and a cheaper plan (less than $10/month, i.e. around $100 of unnecessary annual costs) when not there, and an expensive data plan while there. If it works worldwide (as I hear T-mobile's $70/month plan does), that would be a bonus.

Supporting calling over WiFi would also be good for using the SIM card elsewhere.

So far the strategies I've identified are:

  1. Get a postpaid US number
  2. Get a prepaid number with online refill/recharge and roaming capabilities, so that you can use the sim once in 3 months.
  3. Get an online US number (skype($60/year), google(free + some $ recharge) and use that as primary, forwarding to local throwaway sim while in the US.

My question is are there any other strategies that people have used successfully?

  • 5
    You're not going to get a prepaid SIM which will be valid for 24 months, forget it. Commented Jun 11, 2018 at 13:48
  • I guess that post paid plan is available only after a credit score check, which you probably will fail, which will lead you to big security deposit
    – VMAtm
    Commented Jun 13, 2018 at 14:55
  • 1
    In the end I took the advice of Google Voice + T-mobile as the solution. So far it's working well. The real test will be 6months down the line, will report back then.
    – Vijay
    Commented Jul 22, 2018 at 22:32
  • OK; do you remember what ended up happening 6 months later? Commented Aug 27, 2020 at 20:55
  • It works! You just have to keep paying the $3 monthly fee for keeping the number active. I lost the sim card however after a while, and since due to covid travel to US is difficult, I have to figure out a way to get the replacement sim card sent to me.
    – Vijay
    Commented Aug 31, 2020 at 7:59

3 Answers 3


T-Mobile Prepaid almost meets your requirements currently. Note that their offerings have changed over the years and may continue to change.

First, get a T-Mobile Prepaid SIM by going to a T-Mobile store in the US. They can get you started with "Simply Prepaid" which is currently $50+tax for 30 days of unlimited calls/texts + 10GB data. You may have to pay extra for getting a new SIM.

Before the 30 days are up, log in at https://account.t-mobile.com to pay for the next 30 days. You add the money to a prepaid balance and then it gets deducted when the next 30 day period starts. Repeat every 30 days.

When you no longer plan to use the SIM but want to keep it active, log in and click "Plan" and change to "Pay As You Go" which is currently $3+tax for 30 days including 30 minutes or texts. The change will take effect for the next 30 day period. You have to add at least $10+tax to your balance, which will be deducted $3 every 30 days. I'd suggest to log in every 30 days and add another $10+tax every 60 days to be extra sure your account doesn't get deactivated.

The catch will be how long you can do this without using the SIM at all, which is not 100% clear from their website. I did this for 75 days of no usage and it was ok. Their website currently says "Service available for 30 days after activation/refill/conversion; then account is suspended. If you have a balance, your plan will resume for 30 days with 30 voice min. or SMS messages. After this 30-day period, your account is suspended."

When you want to change back to the $50+tax plan, log in and click "Plan" again.

If you need to change plans and can't wait for the end of the current 30 day period, you'll need to add money to your prepaid balance and then call T-Mobile customer care by dialing 611 from your phone and the representative will make the change for you. They can also help you with other options that aren't on the website like $5 to add 500MB for one day, etc.

  • As a bonus, T Mobile gives out roaming in Mexico and Canada for $5, so you won't need an extra sim to go there.
    – JonathanReez
    Commented Jun 16, 2018 at 3:18
  • @JonathanReez Yes, that worked well for me when I made a short trip to Mexico. But it's not for a long trip as their fine print requires more than half your monthly usage to be from within the US.
    – krubo
    Commented Jun 16, 2018 at 3:28
  • 1
    Their fine print doesn't apply in practice - I'm permanently using a T Mobile SIM in Canada, only traveling to the US once per month.
    – JonathanReez
    Commented Jun 16, 2018 at 5:43
  • This is what I've done in the past, but lost the T-mobile number when i forgot to pay the balance for a while
    – Vijay
    Commented Jul 7, 2018 at 12:21

I use Google Voice as my stable US number and I am happy with that approach. I simply buy a cheap pre-paid SIM card in each country that I visit, including the US.

The Google web page (voice.google.com) is very straightforward; setting up call-forwarding to another number is self-evident.

If you have the voice.google.com web page open, you can also receive incoming calls over the browser.

Even if you don't setup call-forwarding to another number, Google will transcribe incoming calls to text (remarkably accurate) and send them by e-mail to you.

A huge advantage of Google Voice (and the main reason I use it) is that it supports incoming SMS messages in most (but not all) cases. This is important for 2-factor authentication when you are logging in to a US website from abroad.


EDIT: In 2020-2021, Google stopped providing Google Hangouts Dialer and eventually broke existing installations. Fortunately most of the functionality has been moved into the Google Voice App, which is now capable of making calls in data-only mode on both wifi and SIM-based data without making SIM-based calls. Their support information is vague and doubtful about whether you can use it outside the US. As of 2021, it is still working well enough for me to use it, but not well enough for me to recommend it to others. Only time will tell whether Google Voice remains a viable solution for travelers in the future.

What I did is use a Google Voice number. To get one initially, you must be in the US and have another US number, but you can keep the Google Voice number once you have it as long as it doesn't sit unused for too many months.

Rather than dealing with forwarding settings, I got Google Hangouts Dialer for Android, and changed its settings to ring for incoming calls. This enables you to make and receive US phone calls using your Google Voice number, by using the Google Hangouts Dialer app. In this case, don't install the Google Voice app which would depend on forwarding settings and making calls using your SIM card.

The advantage of the Google Hangouts Dialer setup is it only uses data, so you can use it equally well from anywhere in the world that you have data, either Wifi or mobile data. It will work with your throwaway SIM as soon as data is working, both in the US and other countries. The disadvantage is it has slightly poorer sound quality than a regular mobile phone (much poorer if your data connection is bad). The other disadvantage is it doesn't work right with apps like Uber that want to make phone calls directly. I still used Uber but I had to text the driver to call me. The other disadvantage is you can't log into the Google Voice website from outside the US, so you need to make sure you like your settings before you leave the US.

  • I fail to see how this is better that the T Mobile SIM, to be honest.
    – JonathanReez
    Commented Jun 16, 2018 at 5:54
  • 1
    @JonathanReez in particular, this way I can use it as an unlimited US phone outside of North America.
    – krubo
    Commented Jun 16, 2018 at 16:22

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