How to change my billing address from the USA to Thailand

See -> Change your Apple ID country or region

Change your Apple ID country or region - Apple Support (KW)

• You need to have a debit / credit card issued by a bank in Thailand.
• You need to have a billing address in Thailand.

Then -> Sign in to your Apple ID account page and edit / update your Apple ID details.

https://appleid.apple.com

• On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.
• Change also your billing address.

Click here for more support and assistance.

See -> Change your Apple ID country or region

Change your Apple ID country or region - Apple Support (KW)

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What to do before you change your country or region

• Spend any balance remaining on your Apple ID. If you're not sure whether you have a balance, check your Apple Account balance.
• Cancel your subscriptions and wait until the end of the subscription period. 
• Wait for any memberships, pre-orders, movie rentals, or Season Passes to complete, and wait for any pending store credit refunds to process. You can cancel a pre-order.
• Make sure that you have a payment method for your new country or region. See what payment methods you can use.
• Redownload your apps, music, movies, TV shows, and books on any devices that you might use to play or read them in the future. Some types of content might not be available in your new country or region. Learn what types of content and services are available in your new country or region.