Swap to Sim only monthly, from PAYG

[PeJe]

After many years with o2 on PAYG, i decided to move over to Sim Only, pay monthly. I have paid  and Sim will be here  today sometime, and o2 have already sent an email telling me what my new  mobile number is.

I want to keep the number i've had for many years, obviously. So after having called CS , agent said wait till Sim has arrived, then call CS and swap the number back to my old PAYG number.

I had a look on  my account about swapping numbers, and it said " Delete This Device "  ?   or   "Keep This Device "  ?

What on earth does that mean.

If i delete my device ( does "device" mean my phone  or my number ) what happens ?  If i  keep my device,  does that mean i cant swap numbers ?

I'm afraid the website is poor in explanation and finer details, so i have no idea right now.  Agents with CS seem to be just working off a crib sheet.  They're not techs, and a bit of a struggle at times to understand their accents. I'm assuming o2 have shoved their CS centre overseas like everyone else.  What a surprise.

Instead of waiting 20-30 minutes on the phone for someone to answer, ( as has already happened )  it would be so much easier to do this in my account online, but its just too vague. 

For instance, do put i the new Sim in, and only then change my number ?  Or change my number, then install the Sim.

Stumped...

[Cleoriff · Accepted solution]

@PeJe 

Switching from O2 Pay As You Go to Pay Monthly

If you switch from Pay As You Go to a Pay Monthly tariff, we will send you a new sim with a new phone number.

If you want to keep your original number, we can arrange this. You’ll need your new Pay Monthly phone number from your O2 confirmation email or sim pack.

• You can fill in our online form: Switch your number to Pay Monthly.
• Or call us on 202, free from your O2 phone, on 0344 809 0202 from any other phone, or visit an O2 store.

https://www.o2.co.uk/help/device-and-sim-support/how-to-keep-your-mobile-number 

[pgn]

Sounds like you could benefit from the community-generated guides in this area, @PeJe - 

Guide: Sim Swap: a mini guide 2017 update 

Read it through, to get a feel for what it is you need to do, then start with the original SIM in the phone, and proceed from there. If something goes awry, come back to the Forum here, someone will pick it up and help you transfer your PAYG number onto your shiny new SIM-Only SIM. 

And it looks like @Cleoriff has said much the same above whilst I have been typing my answer 😂

Good luck!

[PeJe]

Thanks people, advice noted 👍