Messages synced between iPhone and iPad do not delete on iPad when deleted on iPhone

If you have an iPhone - and both iPad and iPhone are signed-in to iCloud with the same AppleID - to send SMS/MMS messages (green bubbles) from your iPad you must explicitly enable Text Message Forwarding for your iPad on your iPhone...

On your iPhone:

Settings > Messages > Text Message Forwarding - set to ON - and explicitly enable your iPad from the list of devices.

For message synchronisation to work as anticipated, ensure that Messages in iCloud is enabled on both your iPhone and iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

The one and only way to have messages deleted on all your Apple devices when you delete them on one device is to use iCloud for Messages. That is described here.

Keep your messages up to date with iCloud - Apple Support

This will cause your messages to be housed in iCloud and therefore appear the same and have the same status on all your Apple devices.

Note my response differs from LotusPilot’s explanation, as the setting required is:

Settings > [your Apple ID] > iCloud > Messages in iCloud = “on”

Information about SMS/MMS was included so as to provide a full answer. Most queries of this nature are almost always connected to this functionality; many users do not understand the differences between Apple’s iMessage service and Cellular messaging.

Returning to your issue - to reiterate, for message synchronisation to work as anticipated, ensure that Messages in iCloud is enabled on all your devices. For iPhone iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

If settings are as described and the problem persists, return to the setting on each device - and disable the setting. Next, perform a forced-restart of all devices. Only after restarting all devices, again enable Messages in iCloud to ON.

williamfrombinfield wrote:

I did say both devices are signed in to the same iCloud account. By this, I thought it implied/confirmed that on both devices Messages (and everything else) is "ON" for iCloud

It did not confirm you’re using Messages in iCloud. I, for one, use iCloud to house Contacts and Calendars among other things but do not want my messages there.

You’ve now assured us you use Messages in iCloud. I understand.

You need to make sure that you have Messages in iCloud turned on for both your iPhone and your iPad. If you don't have it turned on, then your phone can forward the messages to your iPad, however, that's all it is going to do is forward them. It will let you reply and you'll see the reply on your phone, but you are going to see the exact situation that you are describing. You'll get them forwarded and you'll be able to reply, but if you delete them off your phone, they will not delete off your iPad.

If you have Messages in iCloud turned on for both devices, then when you make a change on one device, it will make the same changes on your other devices. This is what is trying to be described to you in the other posts.

Goto Settings > AppleID (clicking the account name at the top) > iCloud > (under apps using iCloud click show all) then go to Messages in iCloud. Make the changes there that you wish to make and get those devices turned on that you want to use it.

This should solve the issue that you are describing. I don't wish to have my Messages synced this way, but this should fix the exact problem that you are describing and is the fix indicated by the others as well.

williamfrombinfield wrote:

However, I am not stupid. I am quite capable of setting up/configuring my devices correctly.

Stupidity is not even being suggested by anyone. I (a former Mensa member) do occasionally overlook things.

The behavior you have described would occur if Messages for iCloud were not turned “on” on your iPad. Your original post did not even mention Messages for iCloud. You subsequently confirmed it is set correctly.

Make sure iCloud email backup is on on both devices. My iPad was, my iPhone wasn’t. 👍🏻