PAC or STAC - Transferring Tesco Mobile Number over to new O2 contract

[Cliveski]

I have tried to transfer my phone number from Tesco Mobile to my new O2 mobile contract using a PAC code - this didn't seem to work - do I need to request a STAC code from Tesco Mobile instead?

So far I haven't kept my new O2 sim in my new phone - I'm just uisng my old tesco sim (old number) until I loose service and have to swap the sim over.

[MI5 · Accepted solution]

@Cliveski 

You need a PAC Guide: How to get your PAC [June 2021 Update] 

You can subit it online here https://www.o2.co.uk/help/device-and-sim-support/how-to-keep-your-mobile-number

or by calling O2 

All numbers are in this guide Guide: Coronavirus Community Help and Support 
When you call, you will be asked for 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 someone.
You can also try saying "Upgrade" or "Fraud" to be connected to an advisor.
8.00am is the best time to call if you can.

[gmarkj]

A PAC transfers the number from your old contract to your new one.
A STAC cancels the old number on your old contract.