Change over of handsets and SIMS

[KHKate]

I used to use a Doro Easy Phone 508 and recently bought a new handset - a Doro 7080. I thought it would be a straight easy swap, but it hasn't been the case as my old SIM was a standard one, thus too large for the new handset. I had recently ordered a free PAYG SIM (different number) and that did fit in the new handset. Not being aware of needing to activate SIMS, I did request a SIM swap, so that my old number was transferred onto the new SIM card - which happened in about 20 mins after request was made! The new handset receives and makes calls and texts on my old number, but the handset doesn't show the SIM as being there. Online, it still shows the phone number as being in the old handset, but i want it to show the new handset instead. How do i do this please? 

[MI5]

@KHKate 

It should change over eventually automatically but it makes no difference whatsoever to how anything works.

[KHKate]

But I am wanting to pass the old phone onto a friend so they can use it, with a different number. I  thus want to remove the handset from my account, but as it is the only handset shown as linked to my account (with IMEI and PUK), i can't do so. I want to register my new handset with its IMEI (and PUK hopefully) to my old number, so I can then remove the old device. I have a fair amount of credit on my old number, so don't want to just ditch it - which i fear is going to be the only way forward! Technology and seniors do not go well together!

[MI5 · Accepted solution]

@KHKate 

You can do whatever with your phone.

Your number and credit is on the sim card so that will be applicable to whichever phone your sim card is in.

As long as the credit is showing against your phone number which you are using, it's all good.

[gmarkj]

As you say the credit is attached to the number, not the phone @KHKate. Putting the working sim in the new phone means that the credit is on there, not the old one.
o2's systems can take a while to catch up with what phone you are using, but that doesn't mean your credit is at risk.