Great Western Coffee Shop

Just a theoretical question really, but it could result in practical advice.
I sometimes buy a day Travelcard from Basingstoke into Waterloo.
When I return to Basingstoke , the barrier retains my ticket.
If I wanted to return to London later in the day, ( perhaps by car)  would I  then be entitled to  use the Travelcard for the zones that I had already paid for, ?

I would say technically yes.

The assumption being made is that once you have used the return train journey to your starting point, you have completed your day out, but the ticket is still valid for the zonal journeys within the travelcard. Also, it is non-transferable, so only usable by you - retaining the ticket stops you re-using the train journey to/from the zones, as well as passing it on to someone else that might be going to the zones on their own ticket then using your travelcard.

If you can persuade the gate staff that you are driving etc in to the zones later, you ought to be able to retain said ticket for use later within the zones

Thanks Chris, I sort of assumed that was the case, and it may just come in handy one day.

If so, I'll speak to  the gate staff if the barriers are closed.

Far from "technical" and "in theory" for some.

I used to work in Basingstoke.  Scenario - morning meeting in London, afternoon in the office, meeting someone in London and taking in a show in the evening. 

Many years ago so I don't remember what I did about tickets, but current logic would be a travelcard for the morning and a return from Basingtoke to first place in zone in the evening.  I suspect that as the travelcard is a zonal ticket, no need in the evening to catch a train that calls at Surbiton or wherever the boundary is!