The Oyster Extension Permit was a switch which was needed by Oyster users with a travelcard stored on their card and who wanted to travel beyond the validity of that travelcard on National Rail services. Thankfully it is no longer required after TfL managed to persuade the NR TOCs to drop it. It only lasted 505 days and was so poorly publicised that the majority of Oyster users are still oblivious to it’s existance. There is a new page detailing how to travel beyond your zones now that the OEP has gone.
For historical reasons the page which explained all about them has been archived, along with the many comments generated by the topic.
I suggest a quiet funeral for the OEP and respectfully ask that no flowers are sent.
This page updated 11 February 2016.