Columbia University ID Center

Door Status
Card readers at building entrances will display either a red or green light, indicating door status. Solid red means the door is locked. Place your card over the reader to gain access. Solid green means the door is unlocked and no action is required.

Building Entry
To gain access to a locked building, place your card over the reader. One of two actions will take place. Flashing green and red means access is granted, and the door will unlock. A green flash followed by solid red means a valid card is read, but access is denied.

Troubleshooting
If you have an old Columbia Card or if your University ID card has been damaged, the reader will not respond. Visit the ID Center at 204 Kent Hall to have your card replaced or contact us.

If you are denied entrance to a building to which you believe you should have access, contact Public Safety at psa-support@columbia.edu or 212-854-8500.