The link provided in the above post links to advice by one of our Sage Pay Partners so take a look at it.
Token allows shoppers the option of storing their card details (as a token) to their account on the payment page during their first purchase instead of having to set it up manually afterwards. Single click purchases for repeat customers will become much simpler and quicker to set up.
To view the Token Guide go to here, scroll to the bottom of the screen and select the Download the Documents option within your preferred method of integration (server, server inframe, direct). Within the guide it explains creating and storing a token.
If this is a service you would like enabled on your Sage Pay account our New Business team are available 0900-1800 on 0845 111 4466. Prices for Token are available via here. If you have any other questions, our 24/7 Support team can assist to on 0845 111 4455.
Sage Pay Support.