How do I get the base cost?

I recieved a share scheme pay out. I do not have an ITc3? How would I go about completeing the capital gains portion of the document, as I do not have a base cost?

You are unfortunately unable to declare a gain if you dont have anything to base your gain on, therefore you will need to contact the fund/company who paid the share scheme to give you a base cost in order for you to calculate your gain.