Loiding: The Credit-Card Latch Bypass
Loiding is a bypass technique that uses a flat object to retract inward-opening spring-supported latches.
The term loiding comes from celluloid, used for early photographic and cinematic film.
How Loiding Works
A flat shim — historically celluloid, today plastic or laminated card stock — slides into the reveal between door and frame. Angled latch bolts retract when pressure is applied to the beveled face. Outward-opening doors and properly deadlocked latches resist this attack.
Deadlocking Plungers
Residential grade deadlatches include a small pin on the latch tailpiece. When the door closes fully, the pin drops into a pocket and locks the latch so only knob rotation retracts it — not end pressure from a card.
Forensic Evidence
Loiding is often surreptitious: little visible damage if the shim is thin and skilled. Deep scratches on latch faces or strike edges may appear after repeated attempts. Security reviews note door gap tolerances and latch grade.
Legal and Ethical Context
Like lock picking, loiding is a legitimate locksmith bypass for lockouts when authorized. Unauthorized use is burglary tool territory in many jurisdictions. Technicians document chain of custody on commercial bypass calls.
Prevention for Property Owners
Upgrade to deadlocking latches, install strike plates with full lip coverage, maintain tight weatherstripping gaps, and add deadbolts that cannot be shimmed from the gap. See latch mechanisms and deadbolts for hardware context.