Not active new SIM card

[PlamenValov]

The new SIM card is not working and old one is stopped data working,why?

[jonsie]

It can take up to 24 hours

Is this an upgrade?

Is it a porting issue (ports aren't done at weekend)?

Keep rebooting your phone

You can call them if you need to

customer service

Numbers here

 Guide: Coronavirus Community Help and Support 

Advice from an O2 Guru regarding a way to get through:

If you call 202 or any number in the link, when it comes to the reason you are calling stay silent for 15 seconds and you will be taken to the keypad options.

Press 2 for Everything Else

Press 5 for More Options

Press 7 for Anything Else which will put you though to an advisor.

Press Upgrade, Lost/Stolen or Fraud if you have to.

[Sammybabes]

Do you have to activate a new sim ?
I’ve been turning my phone on and off all day but still no service and in settings it’s states no sim restrictions .

[MI5]

@Sammybabes 

A replaceent or new sim needs activating by doing a sim swap Guide: Sim Swap: a mini guide 2017 update