Upgrade/cancel of contract

[Cityman]

I'm in the last 40 days of my contract and I would like to upgrade to save on my monthly bill, I've seen an offer with o2 same as on now minutes /texts wise  but more data, for less money & a new phone, with a 3rd party company,

the same deal with O2 is an extra £12 pm & 36 months contract, which i dont want, 

Can I upgrade through this 3rd party or do I wait till I'm out of contract, when was with EE  i could change in the last 49 days of my contract with no fees can I do the same with O2?

[Cleoriff · Accepted solution]

@Cityman 

You need to get your new contract then call O2 to migrate your number to it which will close the old contract and generate your final bill.

You only pay up to the day you migrate your number from the old contract, then your new contract will be billed from the start date of that one.

Edited to add, all numbers for O2 are in this guide Guide: Coronavirus Community Help and Support 

[MI5]

@Cityman 

You will be billed up to the end date of your current contract as it is not yet complete. 
You can upgrade 1 month early without penalty if you do it directly with O2.