Note: This guide was prepared only to explain how much one can save by linking their Pay as you go Oyster Card with Network Rail Card www.railcard.co.uk/network which costs just £25 per year. Full time Students and anyone less than the age of 25 can also get a better Young person's Railcard. www.16-25railcard.co.uk. You will need an Oyster Card Registered in your name. Please take it to TFL-Tube (NOT National Rail) ticket counter and ask them to link your network card with your Oyster Card amd start saving around £2 per day on off-peak travel in london.