Apple Watch (Cellular) on mobile business contracts in the UK

Hi,

One of the owners of our business has purchased an Apple Watch and wants to use the cellular functionality. He currently uses a SIM on our O2 business contract but it appears O2 business contracts aren't supported with Apple Watches in the UK.

Does anyone know a way around this issue or know of another carrier that does support Apple Watch in the UK?

Thanks in advance,

Andrew