can an iphone be used without a simcard for wifi?

http://support.apple.com/kb/HT3406?viewlocale=en_US

This might help answer your question.

You should be able to use it for everything but making calls on a cellular network, however it may still require a SIM card.

Yes. You have have it do everything internet related, without a SIM card. The SIM just allows phone calls/texting, to happen. I removed a former friend's SIM card, from her old 16GB iPhone 5. After I reset it and set it up, I was still able to access the internet via wi-fi (Facebook, Twitter, etc.). The SIM just gives you data to use, but you can just have it run wi-fi. Once an iPhone runs without a SIM card, i basically acts like an iTouch. The only difference between the 2 devices, is making phone calls (you can still iMessage, on an iTouch).

Maybe if you do not live in Japan but if you do then no chance they lock and refuse to let you use your very expensive iPhone unless you buy a iPhone with a Telephone credit carrier they hate people who want to be wifi freebiesbecause they can not make money they sare like Yaqooza Gangsters and Apple Japan work with them.

Yes. Once activated the Phone can be used without a sim card. All features function except of course making calls and sending texts.

Funnily enough, I have received iMessages, and FaceTime calls from iphone users - though my iphone has no data plan or SIM card, and I use wifi only on iPhone 4S and ipad mini.

But when I try to send I get error messages, no sim!

Do you have Send as SMS turned off in the message settings? That might be be problem. You don't need a data plan to use iMessage. Settings > Messages > Send as SMS.

iMessages and facetime calls work on wifi. Cellular calls and SMS texts require cellular service. Different things have different requirements. If you try to send and and SMS you'll get that error. If you try to call using FaceTime it should work over wifi.

http://www.techradar.com/us/how-to/phone-and-communications/mobile-phones/ask-ho w-to-use-an-iphone-without-sim-card-like…

You can use FaceTime video or audio but you need wifi if you want to use your phone without a SIM card

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