On 9 Dec, 23:49, Richardr wrote:

Do they work at City?

Yes

It's going to be hit and miss, depending on the network, handset and
other conditions. And, between Farringdon and King's Cross TL you
wouldn't maintain a signal all the way - so it's not going to make too
much of a difference.

However, in due course, I'd expect to see proper coverage at these
stations and many more (plus inbetween) - depending on the results of
the Waterloo & City line trial.

Jonathan