How to get a physical SIM for foreigner.

mufufu wrote:

I am Japanese. When I visit the United States, I would like to purchase multiple physical SIM cards from T-Mobile. Can I purchase physical SIM cards by presenting my passport and credit card? I prefer to purchase physical SIM cards rather than eSIM. I have heard that physical SIM cards cannot be purchased unless you are a resident of the United States or hold American citizenship, so I am concerned.

That only applies to postpaid services, which require your Social Security Number or a Tax Identification Number, a credit check, and a US debit or credit card of you want to pay through the website.  

Prepaid SIM's can be purchased by anyone and are primarily used by visitors to the US.  You can purchase as many of these as you want from most retailers or at a T-Mobile store.  Just make sure you specify that you want prepaid SIM cards because postpaid SIM's can't be used for prepaid service and prepaid SIM's can't be used for postpaid services.  

Most international credit cards are accepted in-store.  Online is a completely different system.  

If your getting a prepaid plan you can buy Sim card at about any big box store or grocery store and buy refill cards for the plan.

It's the first time I heard that you have to be a USA citizen to purchase a Sim card but Tmobile doesn't accept some foreign credit cards though.

I understand that it's possible to purchase a physical SIM for prepaid services. Thank you for the information. Is there a way for Japanese travelers to buy a SIM card for T-Mobile's postpaid service?

Depending on how long you're going to be in the USA, prepaid is the way to go. Once funds run out the plan will automatically cancel and for postpaid accounts you will need to call customer service by the end of your billing cycle to cancel or incur another months change.

mufufu wrote:

I understand that it's possible to purchase a physical SIM for prepaid services. Thank you for the information. Is there a way for Japanese travelers to buy a SIM card for T-Mobile's postpaid service?

The problem is that it's somewhat like a non-resident foreigner buying cell service in Japan. In Japan every document requires your resident ID. In the US , every credit account requires your Social Security Number and Credit Report. There is no problem setting up prepaid service but postpaid is a credit account that requires a credit report.