Transport for London has resumed processing new applications for Oyster photocards more than two months after a significant cyber attack prevented customers from using the service.

In September, the transportation agency said that it was “dealing with an ongoing cyber security incident” but assured riders that none of its essential operations were compromised or disrupted.

TfL said it worked with relevant law enforcement authorities, including the National Crime Agency and the National Cyber Security Centre, to respond to the incident, but assured passengers by stating that “there is no evidence that any customer data has been compromised.”

Following an investigation into the cyber incident, TfL confirmed that certain sensitive personal data of its customers were accessed during the security incident. The compromised data included “names and contact details, including email addresses and home addresses where provided.”

“Some Oyster card refund data may have been accessed. This could include bank account numbers and sort codes for a limited number of customers (around 5,000),” Tfl said.

Last month, Tfl said that Oyster photocards for children, students, care leavers, people aged over 60, apprentices and veterans were unavailable and that it could not process new applications until further notice.

In a recent update, however, Tfl said it has resumed processing new applications for some Oyster photocards. “Transport for London (TfL) has now begun accepting applications for 18+ Oyster photocards and several other concessions, as it continues to restore services following a recent highly sophisticated cyber security incident,” it said.

“From today, those applying for new 18+ Student; 18-25 Care Leaver and Apprentice Oyster photocards can submit applications again, and TfL will look to process these as quickly as it can.”

Tfl added that for the remaining users, it will reopen photocard applications in phases and will process refunds for passengers who paid extra in due course.