You mean that you are still in contract with Three until November 13th?
And you are planning to move to 48 therafter?
It's really up to you.
You can activate your 48 SIM now and it will work with the new 089 number that it comes with.
You don't have to buy a membership plan yet - you can defer that until you finish with your old provider and presumably port your number over.
If you don't buy a membership plan initially then you will be able to receive calls and texts and use the free 1GB of mobile data - all on the 089 number that comes with the SIM - but not make calls or send texts.
If you need to contact 48 support about this then see the links in my signature below.
