How can you check if your phone hasn't been cloned?

[Stacy-AW]

I have had people calling me saying that they have missed a call from me. When in fact I haven't called them.

Could it be that someone has cloned my sim or is it a problem with the phone?

[jonsie]

 it's apparently very easy to spoof numbers  and quite a few people have reported your exact problem

[gmarkj · Accepted solution]

I very much doubt that anyone has cloned your sim, or that you have a problem with your phone @Stacy-AW.

Scammers use clever technology to spoof numbers, ie pretend they are calling from a number that is not theirs, and unfortunately yours is the current number they are hiding behind.

At some point they will stop using your number and move on (if they haven't already!)

The only thing you can do is ask o2 to change your number - but this means telling everyone who has it that your number is now different. 

Some more advice below:

Guide: A Guide to Deal with Spam/Scam Calls and Text 

https://www.o2.co.uk/help/safety-and-security/phishing-and-smishing-advice

https://www.ofcom.org.uk/phones-telecoms-and-internet/advice-for-consumers/problems/tackling-nuisanc...

https://community.o2.co.uk/t5/Welcome-News/Phishing-amp-Smishing-What-you-need-to-know/m-p/1436333#M...

Guide: How to change your mobile number