Upgrading to L class fare one way

Is it possible to upgrade a lower fare code class one way ? For example is it possible to upgrade a flight currently fare class O outbound and O class inbound to a L class inbound (at financial cost obviously) or would both legs need to be upgraded to L?
Thanks
DL

[Neil]

Yes you can do that no problem. Of course there will be a change fee and then the additional cost, but it is allowed.

Sorry, I'm new to V-Flyer. What advantages does upgrading to "L" class provide? Is this a different class altogether, i.e. PE to UC, or is it simply that you're given a better seat within your class? Thanks. J

[honey lamb]

Sorry, I'm new to V-Flyer. What advantages does upgrading to "L" class provide? Is this a different class altogether, i.e. PE to UC, or is it simply that you're given a better seat within your class? Thanks. J

No, it is the lowest class in which you can upgrade to either PE or UC

Yes, that should be fine, as well as the fare upgrade component you will have to pay the change fee (usually £120 on specials as opposed to £90 on year round fares).
It also depends who you booked it through. If you did this through anyone other than VS direct then if you upgraded to L class you still wouldn't be able to upgrade. Was it with VS to start with?
E

[Neil]

Sorry, I'm new to V-Flyer. What advantages does upgrading to "L" class provide? Is this a different class altogether, i.e. PE to UC, or is it simply that you're given a better seat within your class? Thanks. J

You can find all the information for each specific fare code, in the Fare Code Section

It also depends what you plan to do with your L ticket. Unless you use miles to upgarde to PE or UC you will be sitting in exactly the same seat .