Cancellation of Tier 2 Visa upon overseas Resignation?

Hello,

I have a valid CoS and Tier 2 ICT visa, and am back in India after working in the UK for 6 months. However, I am now resigning from the company which sponsored me to go to the UK. I have written to them for CoS cancellation.

Do I need to give my passport to my Company or to the British High Commision/ etc.. so that they can mark my Tier2 visa as cancelled? Can't they just cancel / revoke the CoS as I have communicated it to them in writing of my resignation, and it has been accepted?

Thank you for any answers you could provide me. I am really averse to giving my passport to a company where I am resigning from... Unless they need to mark something physically on the UK Tier 2 Visa page, there should be no reason to collect employee passports...

Regards,
ML

You don't have to do anything voluntarily and nor it there anything that is obligatory that needs to be done.

Thank you for your re-assuring reply..