iMessage is now in new messaging pattern, that’s the changing the way to use message app like before. Also it’s very easy to enable imessage from your new iPhone 7 Plus/ iPhone 7 model. iMessage’s different Bubble effect, Screen effect and Send Handwritten messages in decorative outline. For that you must activate iMessage from device settings. Some time “iMessage not working” or “Showing iMessage is waiting for activiation” on screen. So you must go through troubleshooting given in this tutorial.
For Enable/ Disable iMessage on iPhone, Go to the Settings > Messages > iMessage Enable. (As per your carrier rules iMessage activation charge can by applicable or iMessage rate will be charged).
iMessage activation and Related process same in iOS 10 like earlier iOS versions (iPhone 9/ iOS 8).
Fixed: iMessage Waiting for activation, iMessage not working: iPhone 7 Plus/ iPhone 7
Enable/ Disable iMessage
May be your iMessage activation stuck on iPhone before successfully send request to carrier. Go to the Settings > Messages > iMessage (Disable/ Enable).
Re-login iMessage Account Apple ID
Logout iMessage account from apple server and Re-login. Once you enable iMessage toggle you will see iMessage apple ID, by scroll down screen below. Tap on Send & Receive > Tap on Apple ID > Sign out.
iMessage Waiting for activation, status mark about your acrrier taking too long time in iMessage service enable for your Number. So you can enable it on Apple ID by switch to it from Send & Receive option.
Disable iMessage restriction
You already set restriction on account changes, Remove restriction and Activate iMessage (iMessage toggle not accessible/ Read only).
Settings > General > Restrictions > Accounts > Allow Changes. By making this chang we can change iMessage activation status and reconfigure.
Update your iOS
Keep up-to-date with latest iOS version; Check any iOS updates available in settings app. Go to the Settings > General > Software Update (Over the Air)
Or Using iTunes > Connect your iPhone 7 Plus/ 7 to iTunes via USB lightning cable > Summary Page > Option + Update on iTunes. Update iOS 10 on iTunes or Over the Air
Know about iMessage from Carrier support desk, iMessage charge might be enable for international use, are you using iMessage internationally then charge is applicable. You have upgraded your plan still iMessage not working then Contact carrier (Verizon, T-Mobile, AT&T, Sprint or Others) – Check current plan or contact if you upgrade plan request taking longer time.
Update: Date and Time (if you are outside countries or region)
For the international users, keep date and Time updated with regional time zone by set it automatically.
Settings > General > Date & Time > Set Automatically.
Reset network Settings
Auto Fix all network related issues by reset all network settings.
Reset network settings on iPhone 7 Plus or iPhone 7, Go to the Settings > General > Scroll Down “Reset” > Reset All Network Settings. Re config all settings Restart or Force Restart iPhone 7 Plus or iPhone 7.