Why am I still getting text messages on my old Apple iPhone 7?
Getting messages on old Apple iPhone 7
If you are getting messages on your old phone, after having switched to a new Apple iPhone 7, the issue is that iMessage is still active on old phone, simply switch it off by going to settings > messages and turn off the iMessage button.
Deactivate iMessage on old Apple iPhone 7
To stop your former Apple iPhone 7 device from getting messages sent to the new smartphone, on the old Apple iPhone 7, do the following.
Open the settings > messages, and there turn off the iMessage option.
The messages should now arrive to the new device, and stop getting to the old Apple iPhone 7.
Make sure that the phones are connected to Internet, either with WiFi or with mobile network, so the changes will be applied to the corresponding AppleID account, which is the same on both phones.
No access to old Apple iPhone 7 getting texts
If you have no more access to the old Apple iPhone 7, because you sold it, lost it, gave it away, or destroyed it, then you have to use a service from Apple to deactivate iMessage on the old Apple iPhone 7.
When having the new phone with you, go to Apple deregister iMessage service, and in the no longer have your iPhone section, select your country from the drop down menu, enter your phone number, and click send code.
An SMS will be sent to your phone number with a confirmation code, that has to be entered in their online form.
This will deregister iMessage from former devices, and they will stop getting messages instead of your new device.
If nothing worked, contact the Apple support.