Hah, that easy is it! I shall try that next time. Thanks.

I seem to have overcome my issue in the short term… someone suggested I try “flexing” the SIM because there may be some sort of contact issue. Probably not recommended in general but it seemed I had nothing to lose… so I flexed my SIM… popped it back in, for like the two dozenth time, and it worked. I suspect the SIM must be a bit physically flakey in some way. It was definitely flat, so all I can think of the flexing doing is possibly there’s something like a very tiny connection issue between the contact pads and the internal microchip.

So I’ve managed to sign up to the web account now. The SIM is still sending text messages as the wrong number, but phoning out as the correct transferred number. Probably I just need to give it some time.

Hi ​@yvan 

Thank you for getting in touch with us, I’m glad to hear you’ve been able to get things working again, even if only temporarily.

You’re absolutely right that flexing a SIM isn’t something we’d normally recommend, but your reasoning makes sense. If the SIM has a minor internal or contact-related fault, reseating it (or slightly altering how it sits against the contacts) can sometimes restore connectivity. That does suggest the SIM itself may be physically unreliable, so if the issue reoccurs, a replacement SIM would be the safest long-term solution.

It’s good to hear you’ve now been able to access the web account. Regarding the number showing incorrectly on outbound SMS while calls present correctly, please try the following steps for wrong numbr showing:

For Samsung:

Go to the Contacts app, click on your name, then click on Edit and then update your phone no. and Save. Go back to About phone and check if the number has been updated.

For iPhone:

Settings > Phone > My Number, then reset iMessage/FaceTime by toggling them off/on in Settings > Messages/FaceTime, ensuring your correct number is selected for sending/receiving in those apps, and restart your phone

Thank you,

Zandile 

The iD Mobile Team 

Thanks for the info ​@Zandile M - I have a less-common Android phone (BlackView BL8800Pro) which may be a bit different to a Samsung, but I have tried the closest I can find to that process (changed my own contact in the contacts app) and it still sends SMSes with the wrong origin number. It does receive SMSes to my old/correct number fine at least. I’ll have a closer look later on if it doesn’t fix itself, I’ll try another reboot tomorrow too. The SIM info in settings just says there is no number at the moment. If it hasn’t fixed itself by the weekend I may try a factory reset on the phone, it’s about time for a cleanup anyway.

I discovered the problem is with the “RCS” service, it still had the old number. I have no use for RCS really, and I have disabled it for now and my texts go out with the correct number. So it’s an RCS configuration issue and I need to somehow reset that, instructions online are along the lines of clearing the messages app data. But OTOH I don’t really care about RCS so just switching to real SMS works fine for me! 👍

Hi ​@yvan. Thank you for your update and for sharing the steps you’ve taken. If in the future you decide you want to use RCS again, please try the following to reset it.

Enter your ported number and verify with the SMS code. This will de-register your number from the old network's RCS profile.
 
Then this:
To fully reset RCS on your device:
Go to Settings > Apps > Messages
Tap Storage & cache
Tap Clear cache, then Clear storage/data
Repeat for Carrier Services app

Lastly send this:
Open Google Messages
Tap the profile icon (top right) > Messages settings > RCS chats
Turn RCS chats ON
It should now attempt to verify your number via the new carrier
Wait a few minutes for RCS to activate

~Marquerita