You are unable to claim for an intermediate period of non-use for your season ticket and we are unale to extend the end date of a Season ticket. We may allow, for example, in cases of illness, the refund to be backdated if you produce suitable documentary evidence for a period before you hand in your ticket, provided that you have not started travelling again using your Season ticket since your illness. Your rights and responsibilites around refunds are detailed in the National Rail Conditions of Travel
