All train services operated by One Rail in Norfolk are cancelled on Saturday because of a strike.
Guards and conductors who are members of the RMT union are to strike for 24 hours from midnight on Friday.
Staff are angry about the introduction of new mobile ticketing machines and are demanding that a one-off new technology payment is made.
They want set payments while the new system beds down and have rejected an offer of a 1% increase in commission.
Kerry Worrall, from One, says some trains outside the county will be running.
Whole region affected
"The Norwich - London service will operate hourly to and from Ipswich and half hourly from there to the capital.
"Trains on Norfolk and Suffolk rural routes will depend on who turns up for work.
"Passengers are advised to use Central Trains services and change at Ely for other routes."
Staff are also due to walk out on 7 June in a dispute condemned by One as disruptive to passengers in Norfolk, Suffolk, Essex, Cambs and Herts.
Branch lines across the region will be worst hit but by how much will not clear until the day when bosses know how many guards and conductors will be working.
Union members want a "one-off" payment for the introduction of new technology and One sees the new machines as offering better service to customers.