This is a nice deal - when you buy a Nokia Lumia 620 for £129.99 you can snag a free Windows 8 Professional upgrade worth £49.95!
The offer, exclusively available from Carphone Warehouse, is available on either the white or black phone and is subject to a mandatory £10 top up at checkout. You can also get £3.03 cashback on your purchase from TopCashback.
We've talked a fair bit about the Lumia 620 before - it's a great little handset even without this offer! The previous deal from O2 offering a free additional coloured shell rather than the Windows upgrade is still available (as detailed in our previous post) if that appeals to you more. :)