Credit card technique

The credit card technique, known in Spain as “radiografía” or “técnica de la tarjeta” and among locksmiths as loiding, is opening a door held shut only by the latch, the angled bolt that clicks in when the door is pulled to, using a flexible strip slipped through the gap between the leaf and the frame. The Spanish name comes from the X-ray film that used to be used for it.

It works because the latch is designed to give way when pushed; it is not a security lock. That is why it fails if the door has been locked with the key.

How you protect yourself:

• Always lock with the key when you go out, even for a moment.
• Ask for an anti-card latch, which does not give way to the strip.
• Adjust the door so there is no gap and protect that slot where needed.

We locksmiths also use it to open doors that have been pulled shut without breaking anything, always after checking that the person asking has the right to get in. To improve your locking, take a look at our security cylinders or what to do with a door pulled shut.