iPhone PAYG same as Bill pay ?

[RB26DETT]

Hi guys,
Quick question, My dad was due for an upgrade on his Vodafone Ireland contract and as the iPhone was launced on the vodafone Ireland network on the 25th Of March, they had an introductary offer which entitled him to a free 16GB 3GS. This phone is locked to vodafone.

I want to know if it will work with vodafone ready to go ?
Normally the phones he gets on an upgrade work with PAYG...

Is it the same for the iPhone ?
Its due on Tuesday.

Thanks

[RB26DETT]

Anyone ?