Why can’t I send SMS messages with my iPhone

Read this: If you can't send or receive messages on your iPhone, iPad, or iPod touch - Apple Support

You absolutely can. By default, iPhone will send iMessages to other Apple devices. These won’t count towards sms text limits etc. If you want to send sms exclusively, you can turn iMessages off in settings > messages > iMessage.

If green/on, it will send iMessages to Apple devices and sms to all others, if turned off, it will send sms messages only, to all phone types including Apple devices.

So so why have iMessage? People with iPhones, iPads, and macbooks can set their devices so they can send and recience messages from any of their devices and receive from any of their devices. They can start a conversation with their mackbook at work and continue the conversation on their phone later. It also uses wifi or a tiny amount of data, but doesn’t cost towards sms messaging, picture messaging or video messaging.

My my son doesn’t have data on his phone. He also owns an iPad. When at home he always has one of the devices on him. So if we send him an iMessage we know he will get it. If he is out of the house and we don’t know if he has wifi or not, I turn my iMessage off for a moment to send him a sms text message and then turn my iMessages back on. The reason I do this is his iPad would receive the message and show me it is delivered but he wouldn’t receive on his phone until he connects to wifi. Other than this one person, I generally just leave iMessage on. The phone or iPad will determine itself to send to my recipient as an iMessage or sms on its own.

Check if your iMessages is turned on....settings > messages > iMessage

iMessage messages will be blue when sent to someone else using an Apple device with iMessages turned on on their phone. Sms messages will show as green.

You can! It's just that, by default, Messages will use iMessage when it can and SMS/Text Message when it has to.

I can’t send imess