I have recently bought a used blackberry bold originaly on vodaphone, it has been unlocked and i am now using it on O2 pay as you go. I am about to order the tombile sim only plan which includes blackberry email and internet booster. Do I need to de-register my phone so i get a new pin or can i put the sim in and start using it straight away..
Any Help????

The PIN stays with the device forever. You need to make sure the PIN is not connected with the previous owner's BIS. That will cause you problems.

Please take a look at one of our FAQ articles - "Buying a used BB from eBay". That should explain it.

you can get O2 sim only plans with blackberry email and internet, by the way.

Isit an extra bolt onif it is what bolt on isit? isit on buisness or personal

its the blackberry bolt-on. free on plans above £20, and about £10 on plans below.
Personal.
I was considering moving because I could get more for my money with O2 than t-mobile.

i.e. 150 minutes, 300 texts and the blackberry email and internet booster for £27.50 a month.
O2: 600 minutes, 1200 texts, and blackberry bolt-on for £20 a month.