Hi, if you get a 16-18 zip Oyster card and you currently have a 11-15 one, do you have to order it before your 16th birthday or when the 11-15 card expires (you will still use it when you are 16 if need be). This goes to anything else like this too btw.
You can order a 16-18 zip card at any time during it’s validity period. If it’s being ordered as a replacement for your 11-15 zip card then it should be ordered shoertly before the other card expires. This will be the end of September following your 16th birthday. This is so that any school verification can take place before the 16-18 card is issued.