Forward calls from one number to another

[Francophile]

Hi - I have an old 2G mobile on 02 PAYG that I use for most of my calls and a mid-range Samsung 4G mobile on an 02 MONTHLY contract.  Unfortunately I am stuck in France due to coronavirus, the old phone has almost died and so I can't just walk into a UK 02 shop, buy another phone and get a new style sim card for the old number.  My friends and family only have the old number, the bank uses it to send me confirmation codes and I am awaiting my husband's hospital blood tests on it, so it's absolutely vital to have access to the calls and texts.  Can one number just be forwarded to the other until I can get back to the UK and buy a new phone? Thanks.

[Edit: topic title clarified]

[jonsie]

You can forward the calls from the monthly contract to the P&G but not the other way round @Francophile 

[Francophile]

Thanks, Jonsie.  So if I pay O2 to upgrade my PAYG phone to pay monthly, will I be allowed to forward the calls?  Unfortunately the current pay monthly phone is fine but the PAYG is struggling, so there wouldn't be much point losing access to both of them.

[jonsie]

You could change to pay monthly but it would need a new sim card as they are different Unfortunately they will only send the sim to your UK registered address. Unless you have someone who can post it to you it wouldn't really be an option for you.

[O2Lorna]

yes you will be able to forward calls if you change the payg to a contract, however that would require a new sim being sent.

https://community.o2.co.uk/t5/Other-Products-and-Services/Coronavirus-Covid-19-Community-Help-and-Su...

[jonsie]

But @Francophile is in France so not really an option Lorna.

[O2Lorna]

Yeah you are correct, my mistake.