Ref a friend

[ChristC]

I referred my brother to sky, he had install on 30th September and we have not recieved our voucher.

[Mark39]

"Your friend needs to be new to Sky - subscribing to Sky Mobile, Sky Glass, Sky Stream, or Sky Broadband - and once they're set up, within the 2 weeks after their cooling off period has ended, you will both be rewarded."

https://www.sky.com/help/articles/introduce-a-friend

Cooling off period is 31 days.