moving PAYG SIM to new phone

[G_I]

I live in the US but travel to the UK a few times a year to visit friends from when I lived there. I have a US eSIM and an O2 PAYG SIM; my US provider is Google Fi. Everything was working well with my Pixel 6a, but I've just switched phones to a Samsung Galaxy Flip 5. How do I get the new phone to recognize the O2 SIM and register on the network properly?

[madasaf1sh]

@G_I 

Where did you buy the Flip 5 from as it could be sim locked in the US.. As the sim should just spring to life, and it should then pick up the network.. 

Have you also made a chargable call  last 6 months? as if not as per the t&C's the line will be disconnected

[Oxonian]

@G_I 

Have you tried putting your O2 PAYG SIM back into your old handset - or into an alternative 'phone - in order to establish if it is still live ? 👍