Simon Lee wrote:
Today I needed to travel from Euston Square (NOT Euston) to Leicester
Square.
I got on a circle line service to Kings Cross St Pancras to change for the
Piccadilly Line.
When I exited the circle line platforms, I passed through the barriers and
then again through the barriers for the Piccadilly line.
Because I passed through two sets of barriers, I have been charged £3
(Oyster Card Pre-pay) for a £1.50 journey.
Changing between sub-surface and deep level tube lines at Kings Cross isn't
a change I make regularly so can anybody explain to me if I have done
something wrong here (I just simply followed the signs marked Piccadilly
Line that took me through the barriers) or is this a problem that needs
resolving?

You did exactly the right thing for someone making a journey between
those stations (I assume you have mobility issues/heavy things to
carry: for a typical able-bodied adult, then the walk to Warren Street
or Euston is far quicker and easier than changing trains).

Are you *sure* the system charged you £3? The barriers at KX are set
up so that they don't charge Prepay customers extra in this kind of
situation, and have always worked for me.

Check your Oyster card on one of the machines: if it does show a
journey Euston Square - KX and a journey KX - Leicester Square, then
ask at the ticket office and they'll refund you £1.50.

--
John Band
john at johnband dot org