@Anonymous User Are you trying to add a voucher to an already active pass? You can only add a pass/voucher if the current pass has less than 30 days to run. Also, you can only add one pass at a time. If neither of these apply, do you get any error messages?
If you post the error message, it should help in diagnosing the problem.
Had the same problem myself , voucher code would not go in as Now tv said I am still on a deal and can't use the code unless within 30 days of it expiring but it ends tomorrow 28.09.19, can' get help over the phone and live chat is a joke - can' access that at all. I am now trying to get the email address for Now tv as it seems it's the only way to get help