@Anonymous User
Welcome to the forum.
You can normally apply a voucher code in the last month of any current offer you have applied to your account, however there seems to be a slight bug where the apply voucher link isn't appearing during that last month.
You can either cancel the pass now, and then once it expires in a few weeks time the apply voucher code will be visible again. Or you can ask live chat to apply it for you.
If you want to ask live chat, go to the following help page
http://help.nowtv.com/article/None-of-the-above
and click the green Contact Us button near the bottom left of it (not the How to Contact Us link right at the bottom as that takes you somewhere else) then choose the Live Chat option on the following page.
Just as an aside, if you are going to be outside the UK for your holiday, you won't be able to access the NOW TV service from your holiday destination, so if there's no-one left at home to watch you might want to cancel your pass and apply the voucher when you get back instead.
