Bang to rights, I'm afraid.
The Zip scheme was introduced on 7 January 2008 to provide young people that qualify for concessionary travel on TfL services with an Oyster photocard that confirms their eligibility to access free or reduced rate fares. Young people over the age of 11 who travel while not in possession of a Zip photocard or an alternative valid authority to travel may be issued a Penalty Fare Notice or prosecuted.
The penalty fare is £80. This will be reduced to £40 if you pay within 21 days. Penalty fares increased from £50 to £80 from the 2 January 2012, this will be enforced from 19 February 2012.
http://www.tfl.gov.uk/tickets/14436.aspx
Access to concessionary travel is not an entitlement. It is a privilege that must be respected. With a Zip photocard comes the responsibility to behave considerately and in such a way that does not adversely affect fellow passengers. For this reason, all participants in both the 11-15 and 16+ Oyster photocard schemes (and the older 14-15, Under 14 and Child Oyster photocard schemes) are required to sign up to a Behaviour Code as part of the application process.
The Behaviour Code states that expected behaviours include, but are not limited to, the following:
Look after your Oyster photocard - If it is lost, stolen or damaged, report it to TfL immediately even if you do not plan to get a replacement straight away
Use your Oyster photocard correctly - Pay the correct fare if you do not have your valid photocard with you or it is damaged
http://www.tfl.gov.uk...nforcement-policy.pdf
BTW Zip Oyster 11-15 has no geographic limiting criteria for applications - residents anywhere in the world may apply for this concession of TfL services.
http://www.tfl.gov.uk/tickets/14310.aspx