These season tickets offer an extra discount off the normal child rate fare (and a very good discount indeed off the cost of the adult fare, which becomes payable as soon as your DC turns 16, for some on the first day of year 11
). You can also purchase PlusBus add-on tickets from the website, e.g. to use on the bus between Southend Victoria and SHSG.
One of the great things is that the season tickets are just that, they can be used at any time during the validity of the ticket for travel between any of the stations on your route - so, perfect for meeting up with your new schoolfriends at the weekend or in the holidays without the need for mum or dad to get the taxi out.
All you need to do before you book the ticket is make sure that your DC has a valid child photocard (or adult one, if appropriate) which is free from stations, as you will need to enter the number as part of your DC's details. You can 'trial run' your journey without the photocard number, though, to check how much your ticket would be.
(Please be aware that these tickets are only available from website or from the contact phone number given on the site, not from the c2c or normal Greater Anglia websites, or from any railway station).