I am wanting to go to zwolle from England by train .where do I need to contact to find the cost?
Yes and check on Eurostar for fares including the ADS (Any Dutch Station) option. Sometimes possible. For a relatively small fee extra all the way to Zwolle; first IC train to Roosendaal from Brussels and from there direct IC to Zwolle.
All the best,
<Erik> & [Sandya]
If you book early enough on the NSHispeed site you will get a return for 99 euro. This covers the Eurostar and Intercity trains but not the high speed Thalys from Brussels. Tickets go on sale four months fbefore travel and the low fares tend to sell out quite quickly after that.
One strange anomally, it is often cheaper to travel from anywhere in NL to/from London with these deals than to just travel on the Eurostar to/from Brussels.