"iMessage needs to be enabled to send this message?

Thank you! This worked, although when I turned iMessage back on after doing the reset, I didn't wait for it to activate before I turned the phone off and back on. Maybe it's just the reset itself that got rid of the problem. (I was having the problem of not being able to text without activating iMessage to only one of my contacts.)

Two years after the OP and I am also encountering this problem. I have an iPhone 6plus on iOS 9.0.2

I want to send my husband a message as an SMS because he is travelling internationally and has his data turned off. He cannot receive iMessages unless connected to WiFi. He can receive SMS anywhere at any time via his cellular network.

If I am quick enough, I can hold the message as it is sending and get the 'send as text' option. If the message has already gone to the Apple server, with the status 'delivered', I lose that option. 'Delivered' means Apple have the message on their servers, it doesn't mean it has been received by my husband's phone.

That all being a pain, I normally turn off iMessage while my husband is abroad so messages I send him automatically go as SMS. But all of a sudden, if I turn off iMessage and try to send a message to my husband, or anyone else with whom I have previous iMessage conversations, I get the alert that iMessage has to be turned on to send the message. The phone is preventing me from sending SMS messages. Which are technically a feature of my carrier, not my phone.

I have tried all the fixes listed in this thread EXCEPT deleting the conversation thread. That's just not an option for me. I'm going to report this as a bug to Apple, because there is no technical reason why this should be happening. And then I'm going to download a different messaging app for SMS.

Anyone found a solution that works other than those listed here?

can someone help me I have questions I have iMessage and I am use wifi connection can I use my iMessage to receive iMessages from people for my business that I have on kijij please help me on my questions thank you to my email since no sin card that work

Delete the message string to the person you are trying to message. You do this by swiping left on the right side of the message list. You can then create a new message and be able to send it by MMS. This worked for me. Good luck!

Here is how I just fixed...

Went to try to enable iMessage under Settings>Messages but it gave the error to do over wifi and activate cel data, I clicked the link, it then opened Settings>Cellular

I scrolled down to think I would be to find iMessage or something in the list , I did not... But I found oddly enough "Settings" was turned off to use cellular data... very odd, so I turned it on, then navigated back to Settings>Messages and then switched on iMessage again... now I got the "Waiting for activation" note, and about 5 seconds later, it activated... Go figure

Never ran into this before, but might be linked to low power mode as today was the first day Ive ever experimented with it, so perhaps its a bug that does not reenable certain things once low power mode is turned off... just a guess but everything working now.. no need to reset any settings.

@sabinscabin This was spot on and helped me.

To help others, in settings I did the following:

1. General > Reset > Reset Network Settings (this will delete any Wi-Fi passwords stored on the phone, so do this if the following 2, 3 and 4 don't work for you)

2. Mobile Data (switched it off)

3. Wi-Fi (switched it off)

4. Messages > iMessage (switched it off)

I then switched the phone off by holding the power button and sliding off, then I switched it back on and sent a message to the person that it wouldn't send to without iMessage being on. As @sabinscabin then said, while the message is sending it will stall at about 85% so I pressed and held the text bubble and chose 'Send as text message'. It worked!

I simply then switched Mobile Data and Wi-Fi back on and all messages are being sent as texts now. You'll know if it's worked because as you type the 'Send' button will be green rather than blue.

Thanks. @sabinscabin

If you have Imessage enabled and facing this issue then:
Go to messages > Send & Receive > "Start new conversation from" select email here not phone number. Thats it! now delete the old conversation and start new conversation, now if you turn your wifi off it will fall back to sms and when u turn wifi on will send it as imessage.

I turned Facetime off and toggled iMessage on/off and it now works for me ok 😎

This worked! Thank you!

This routine did not work for me - still can't send non- iMessage texts.

I think this is the opposite of the problem - iOS8 will not send SMS when both iPhones have iMessage disabled.

Yes, in fact I re-entered the password before I tried sending the text. When I opened messages it was normal looking with no imessage in the box.

Maybe you have a different iPhone? Mine is a 5s.

Sure it will. as long as your phone plan has texting. I tried all the other things here to like turning off FaceTime. (which I left off) so It may be a combination of settings. Keep trying!