According to their transport information:
You may take as your hand luggage at no additional charge objects
which are easy to move – those which may be freely placed above and
under the space occupied by you in train.
When I have to pay for my luggage?
- If you transport objects which are
easy to move but cannot be freely placed above and under the space
occupied by you on train. In that event an extra fee of PLN 5.10 is
charged for each oversize item;
- When transporting one unfolded and
unpackaged bicycle (details and instructions on the transport of
bicycles can be found in our "Guide for bicycle owners").
If you don't pay beforehand:
In the event that a passenger has not paid a fare at a ticket window
for the transport of an item, the intention that this be transported
should be reported to the conductor prior to the journey beginning,
i.e. before entering or immediately after entering the train. A ticket
for the transport of an item on an EIP train may be purchased at a
ticket window only.
Please be reminded that an additional charge of PLN 10 is made for the
issue of a ticket from a conductor on a train.
If you fail to do that, then fines are incurred:
In the event that a passenger has not forewarned the conductor of the
intention that an item be transported, then – besides the charge for
item transport of PLN 5.10 – an additional charge is also made, set on
the basis of the directive of the Ministry of Infrastructure of 20
January 2005. The charge at this point amounts to PLN 52, and in the
event that settlement of the amount due is refused a summons is issued
– a protocol with an additional charge of PLN 260. If the passenger
pays the charge within seven days of the date of issue of the summons,
the charge amounts to PLN 65.
To be honest, I can't imagine anyone ever pays for this unless there's a separate luggage car which I don't think there is.