We understand Wai Ming Lee's concerns about privacy (Oxford Mail, March 29) and as a result of his helpful suggestions to us, we have reduced the amount of information we send out in renewal e-mails. In fact,the key safeguards the passenger.

In the past, if a season ticket was lost or stolen, nothing could be done about it. Now the key can be cancelled swiftly and a new card issued.

If it is an annual season ticket, that is a considerable saving and reassurance to the cardholder.

For obvious reasons, we need to hold some information about customers to check they are the genuine cardholder.

We need to confirm the details when they first register, but we've decided this information doesn't need to be resent every time the card is topped up.

We acknowledged Mr Lee's first email within three hours and started to look into the points he raised.

We got back in touch with our thanks and to explain what we had done as a result of his comments, but not as quickly as we should have done.

With the benefit of hindsight, we should have kept Mr Lee in touch with what we were doing in the meantime.

We had put changes in place before his letter was published.

We hope this explanation reassures Mr Lee and the thousands of passengers who successfully use the key every day.

LOUISA WEEKS Operations director Oxford Bus Company