The other evening, I turned up at Kingston (upon-Thames) station,
needing a ticket to Leicester. The booking office was closed, so I
bought a 5p permit to travel. The problem came when the BR booking
office at Vauxhall was closed too. I sweet talked the LU lady at
Vauxhall into letting me through the barriers and the LU bod a KXSP
didn't seem to have a problem with it either (thank god). The St
Pancras booking office was also closed, but I finally managed to get a
ticket at the barrier before boarding the 2340. It all worked out
nicely, but it seemed to me like I shouldn't have been able to do that
(who was to know I wasn't actually wanting to get to the King's X
area, for instance?). Does anyone know what I ought to have done?

I think that the status of National Rail PTTs is not clear on LUL
services but I think that what you did was correct. What you should
be required and able to do is buy an LU ticket for the LUL portion of
the journey and then get that credited against the cost of a National
Rail ticket along with the PTT.

Even better would be a general rule that any ticket(s) can be credited
in full against the cost of any other ticket that has greater
validity.

If I'd bought an LU ticket, it would have got swallowed at KXSP, so
that would've been another £2 down the drain. (I could almost get a
pint for that at St Pancras!) Sometimes I think New York has it right
with their Metrocards which you never let go of as you swipe them.

Even if I had managed to retain an LU ticket, I doubt MML would have
been kind enough to redeem it, and I probably would have ended up
having to write to two different customer relations departments, which
really wouldn't be worth it over two quid.

What I should be able to do, which is seemingly impossible, is to buy
a BR ticket at Vauxhall Underground, just like you can buy LU tickets
from the BR booking offices at Richmond and Wimbledon.

I've just realised something quite shocking. If I'd got onto
Thameslink whilst within LU fare control and changed at Luton (I had
plenty of time - there's a big gap before the 2340), I could have got
from Kingston to Leicester for 5p. This really takes the ****. No
wonder our railways are losing money.