Sim cards

Hi, thanks for membership to your forum.

I have a prepaid T-Mobile cell phone with a US #. I plan on traveling to Panama, Argentina and Costa Rica.
While I am there I would like to use this phone to make calls to the US and have my US telephone # come up on the receivers caller ID. I do not need a local # and I do not want to use another US #.

Would anyone know if a sim card inserted in the prepaid unlocked T Mobile phone would allow for this.
And where exactly can I but this sim card.

I have heard they are not available in Costa Rica, does anyone know how to make it work there.

I also have a Verizon phone with regular service if that may help.

All suggestons appreciated.

Thanks for your help
Charles

If your phone is unlocked, you can get a sim card(s) from a service provider in the places you are visiting, and use them there. It will be cheaper than using tmobile, since T-Mobile is $1.49/min international + roaming charges. =)

im not sure if t-mo prepaid offer international roaming and check with verizon if they have international roaming on there service. what i know if you have t-mo plan and they can activate the international roaming for free.

T-Mo does not allow international roaming on a prepaid plan, AFAIK, you will need to check with them to be absolutely sure. To use your phone you will need to get it unlocked first, and then put in a sim from either a local carrier or from one of the outfits that sell low cost international prepaid plans. And that will work only if your phone will work on the frequencies available in the countries you are visiting.
As far as Verizon goes, they use CDMA, which is not used in most of the world. Thus their international roaming is very limited. And a check at the verizon site shows that they do not roam in the countries you want to go to.
To find out what you need to travel go to GSM World - the website of the GSM Association and check the maps and frequencies of the countries you are going to against the T-mo phone you want to use. If they match, get the phone unlocked and then get a low cost prepaid sim for it. it will not have the same number you have now, unfortunately.

No international roaming with Tmobile ToGo. And there in't a way to get your # to appear with a different SIM AFAIK. Tmobile will unlock your prepaid phone for free, no questions asked, as long as you have had service for at least 3 months and a refill in the last 30 days. Then you can use other GSM services operating on compatable frequencies to your phone.