Tristán White wrote:
I was going to Canning Town to Charing X yesterday, on my PAYG. I realised
when we got to Southwark that it would be quicker for me to get off, go to
Waterloo East platform, and take the train to Charing X, rather than go to
Waterloo, and walk down that travelator etc all the way to the Northern or
Bakerloo platforms, to go northbound on the tube.

But in the end I dared not do it, in case the PAYG was invalid.

It was so annoying, as I ended up being late for my appointment in Charing
X, as there were delays, but had I changed at Waterloo East I'd have got
there on time.

Would I have been able to use PAYG?

Might have been better to walk over the bridge to Charing Cross.