Kids for a £1 with Southern help please

[northernrail2009]

Just seen the £1 for kids offer on Southern website but would like some help with it please.

Could i buy myself(Adult with Railcard) from Watford to Portsmouth on Southern service using the offer of 10% off Advance and then buy the £1 kid ticket for my son to travel from Watford to Portsmouth on southern service?

or can the 2 offers not be mixed?

 

[GadgetMan]

Up to four children (aged 5 – 15 years old) may travel Off-Peak anywhere on the Southern network for only £1 each when accompanied by an adult with any valid ticket (including season tickets).

Child £1 tickets can only be bought from the station, so, to save the most money when booking, buy your adult tickets online and then buy your children’s £1 tickets from the station on the day you are travelling.

The above is from Southern's website. I have highlighted the bits relevant to you. SO it would appear that as long as an Adult has a valid ticket and you are traveling at an 'Off-Peak' time then its fine.

 

[northernrail2009]

The above is from Southern's website. I have highlighted the bits relevant to you. SO it would appear that as long as an Adult has a valid ticket and you are traveling at an 'Off-Peak' time then its fine.

So can i buy the £1 kids Tickets from any Station in the UK or is it just Stations that Southern use like Watford?