I have an iPhone 6 that I bought at one of the little shops in MBK a while back. It's "unlocked," so I only had to get DTAC to make a micro SIM for it and pop it in and it worked. (I have no contract with DTAC; I "top up" my minutes periodically via my SCB Bank account online, which is quite convenient. BTW, I rarely turn on cell data.)

I think they said it originally came from Hong Kong. I'm going to the USA soon. Do you know if I can use my iPhone 6 in the US? Will I need to buy a SIM card from someone like T-Mobile or AT&T? Ideally, I just buy a SIM card, pop it in, and now I have a US telephone number. Or, do you think I'd have to get into an expensive contract? Or, because it's from Asia, it won't even work? Pay-as-you-go would be ideal, if possible.

It will work fine on at&T and t-mobile, verizon and sprint may have issues

My fiancé has phone service in Thailand.When she comes to the US she just keeps on using the Thai

Phone company.It's not cheap but she don't make many calls

When I travel there I pick up a sim card from the local T Mobile Store and a 1 month unlimited plan for phone and data. It is quite reasonable.

Make sure you get a U.S adapter for it (110v) as you probably have a 220v one currently .

I

Make sure you get a U.S adapter for it (110v) as you probably have a 220v one currently .

I

Almost ALL mobile phone chargers are variable current 100-250. Obviously you may have meant the plug adapter to plug it in..

Your iPhone 6 (A1549) will work in the U.S.A. (on LTE, GSM and W/CDMA networks) assuming you get a Nano SIM, activate it, subscribe to a plan (pre-paid, no contract, PAYG) and have coverage. Your DTAC SIM will roam in the U.S.A., assuming you have activated International Roaming (*118*9# SEND), but it will be quite expensive.

In the U.S.A. both the calling and called parties pay.

The phone scene in the U.S.A. has changed quite a bit over the past few years making it a bit simpler, and there are many, many, many MVNOs that allow you to BYOD, and resell service on AT&T, T-Mobile Verizon and Sprint.

A specific recommendation would depend on length of stay, data requirements, exact location(s), budget.

T-Mobile, either directly or via one of their MVNOs like StraightTalk or Simple, might be the best option. It is pretty easy to get an unlimited calling, text and data (1.5 - 3 GB) in the $40 - $50 range for 30 days. T-Mo as some daily options as well.

You can get a 3 way SIM with activation code for free from T-Mo (use the freesim promo code) https://www.t-mobile.com/cell-phones/t-mobile-3-in-1-sim-starter-kit.html , or on eBay for $5. You need to be in the U.S.A. to activate this, but it can all be done on line easily.