My Oyster card has stopped working. What is going on?
If it does not beep when you touch the reader the card has stopped working. There are various reasons for this. Just go to a Tube station ticket office to have it replaced. They will you a new Oyster card free of charge with all your credit restored on it. The only thing that can not be replaced is a daily price cap. If it beeps, but still does not open the gate, then you are probably just low on pay as you go / prepay. Look out for Oyster card error codes 24 and 36 which flash up on the gate if you have too little prepay / pay as you go to enter.