This is currently theoretical, because the ticket I've opted for isn't available on Southern's Key card.
But suppose I had a Key card with say a Brighton > Victoria season ticket, and nothing else, and not activated for pay as you go.
And imagine I started my journey at a station along the route - fine, it's a season - that wasn't barriered, and forgot to touch in.
Or that I ended my journey at a station along the route - fine, it's a season - that wasn't barriered, and forgot to touch out.
http://www.railforums.co.uk/showpost.php?p=1308127 suggests that you must (in bold) touch in/out.
So what would the effect be if you don't?
Does a season ticket on the Key become invalid when you touch out and not become valid again until you touch in?
If you don't touch out, does touching in the next morning actually mean you're touching out? After all, you can break your journey on a season ticket, including overnight!
Is a penalty fare a possibility? Even though you actually do hold a valid ticket?
But suppose I had a Key card with say a Brighton > Victoria season ticket, and nothing else, and not activated for pay as you go.
And imagine I started my journey at a station along the route - fine, it's a season - that wasn't barriered, and forgot to touch in.
Or that I ended my journey at a station along the route - fine, it's a season - that wasn't barriered, and forgot to touch out.
http://www.railforums.co.uk/showpost.php?p=1308127 suggests that you must (in bold) touch in/out.
So what would the effect be if you don't?
Does a season ticket on the Key become invalid when you touch out and not become valid again until you touch in?
If you don't touch out, does touching in the next morning actually mean you're touching out? After all, you can break your journey on a season ticket, including overnight!
Is a penalty fare a possibility? Even though you actually do hold a valid ticket?