Bill Woods wrote:
Eight weeks seems far less than a computer could hold.

Maybe TFL decided that after 8 weeks everyone would have had plenty of
opportunity to query and correct any unresolved journeys so there isn't
much point keeping the details on file.

There are a lot of Oyster cards out there and each time it is touched
on a tube / bus / tramlink / dlr / national rail that supports prepay
reader a record is stored. The amount of space used up for millions of
people's transactions is likely to be substantial so it would seem
quite sensibly to destroy after a given time.

Of course if they do store more data than they give out in a statement,
you are quite entitiled to apply for it (data protection act) but they
are allowed to charge