Unfortunately you can´t purchase a senior pass in advance. You must be 60 years old or older to make the purchase.

I thought that had been fixed but it appears is hasn't. In any case, contact customer service to ask how you can buy a discounted senior pass now:

https://eurail.zendesk.com/hc/en-001/requests/new

OR: if willing to use that old-style paper pass, buy from a GB selling agent who may be able to help out for that. Other as many now think there is no need to buy only from that EUrail centre.

As small comfort: there usually will again be a discount sale a week or so in spring-has always been the last yrs.a

Hi @Graham Leather 

The product team is aware of this, and changes will be made in the future. 

For now you can contact customer service as @rvdborgt suggested. My colleagues will be more than happy to advise you on how to purchase the Pass. 

Have a lovely day!