Why "No Service" with other SIM card?

[owenxguo]

I knew both Verizon iphone 5 and 5s are unlocked, and I was trying to receive a few security text from paypal account in China, when I insert my China sim card, it always show "No Service". But when I plug the sim into my old iphone 5, it worked great. I have a trip to UK and China again later this month, and I will have to use the 5s with me, so I was curious how to resolve the problem??? I know the phone is unlocked otherwise it should say “invalid sim card" other than no service. Could anyone help?

[#2]

*611 or 800-922-0204 and ask for tech support.

Good Luck

[owenxguo]

I'll try again tonight if doesn't work I'll call them, thanks.

[#4]

No problem, Good Luck.

I was under the impression the iPhone 5s was an unlocked version for global use so its strange you are having the issue. But wouldn't a china sim have to be used in China? And not the USA.

[owenxguo]

I have international roaming package, because many China's online banking activities require security code through texts. It was strange that it works on iphone 5 but not 5s.