Iphone Sending two text messages to everyone

[P_R_S_20]

Hi, I've recently ported my old phone number to O2 and since it has ported every time I send a text message to anyone they receive 2 messages. Any idea why this is and how to stop it? I've taken the SIM out cleaned it and reset the iPhone but it's still doing it. Any help and guidance would be appreciated. Thank you in advance.

[Oxonian]

@P_R_S_20 

You need to contact O2. Unfortunately, this is a customer to customer community so we cannot access your account.

You can message O2 on social media :-

Facebook : https://o2uk.co/O2CFB

X (previously known as Twitter) : https://o2uk.co/O2CTW

Instagram : https://o2uk.co/O2CIG

You can also 'phone on 202 or 0344 809 0202 if you are a contract customer or on 4445 or 0344 8090222 if you are PAYG. 

A complete schedule of how to contact O2 is in :-

Guide: How to find help & contact O2 

[MI5]

SMS or iMessage @P_R_S_20 

[P_R_S_20]

SMS

[MI5]

@P_R_S_20 

Duplication is usually because the receiving network doesn't send a handshake back to the sending network to say it's been received.

As this happens on all sms to all networks? I'd start with getting a new sim or trying with a physical sim if using an esim or vice versa.

Pop into your local O2 store with photo ID for a free swap.

[P_R_S_20]

OK, Thank you for your advice!