Old iphone 5 (IOS 9.2.1) to new Iphone 6s (IOS 9.2) no compatible icloud updates

Hi,

I have just bought a new iPhone 6s and want to transfer my SIM card from an old IPhone 5, which is running the latest IOS 9.2.1 software.

However, it won't sync my new phone as it says there are no compatible iCloud updates - as they are from a higher version of the software. How can I update the software on the new phone without a SIM card in? What do I need to do?

Thanks