I don’t buy in to the “it’s a iPhone” issue story. It is entirely a carrier issue.

I tried SIMS from different carriers in the phones and it worked perfectly. I put the iD sims in other phones that previously worked and they failed. The fact that I had exactly the same issue on 2 brand new iPhone 16s at the same time seems a bit of a coincidence too.

i got this resolved because I was a pain - posting regularly with lots of details and getting on the Live Chat daily. I got a different answer from every support team member I spoke to but after a couple of weeks it miraculously worked and has been fine ever since

Thank you WelshPaul!

Ok, very weird. I followed these steps and it now appears to be working for me too! It’s a bit intermittent, but I have checked by calling myself from a landline and the calls are forwarded correctly.

Another quick question: If I am roaming and I have call forwarding of my mobile calls to a UK landline, do I get charged for making an international call back to the UK for each incoming call while I am away? (ie: do I get charged for the proportion of the call that goes from my mobile phone number to the number I am forwarding to? Or do the incoming calls just automatically get forwarded in the UK and therefore only count out of my bundled talk minutes? Or do I not get charged at all for incoming calls even if I forward them to a UK landline number?)
Thanks.

Hi ​@dyc 

You would be charged at the standard rates.

https://www.idmobile.co.uk/help-and-advice/call-charges

Tom