Oysters cannot be recharged at Barking. (I was wrong: Eek!)

You can recharge Oyster at the ticket windows of Fenchurch Street, Limehouse,
Barking and Upminster.

Some of the ticket windows have "No Oyster" signs on them. If you get to the
front of the queue and one of these becomes available you have to let the person
behind you go past and wait for one of the windows with the Oyster equipment
to become free.

There are no self service machines that are Oyster compatable at these stations.

The staff also get things wrong like demanding photocards.