CPL Cheat Sheet 2026

The 30 highest-yield CPL facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the primary ethical obligation of a CPL professional when a conflict of interest arises during commercial security solutions activities? → Disclose the conflict to all relevant parties and recuse from the decision if necessary
2. What is a 'proximity key' or 'smart key' system, and how does it differ from a standard transponder key? → It communicates passively without requiring key insertion, enabling push-button start
3. During rekeying, a locksmith discovers one pin chamber has a driver pin that is too short. The most likely symptom of this defect is: → The lock opens without a key (false set)
4. What is the function of the plug follower in cylinder servicing? → To hold the driver pins in place while the plug is removed, preventing them from falling
5. What is 'door prep' in the context of lock installation? → The process of drilling and routing holes in the door for lock components
6. What should you do if a lock is jamming frequently? → Clean, lubricate, and adjust alignment
7. When installing a mortise lock in a commercial aluminum storefront door, the locksmith must first consider: → The door stile width and thickness
8. In key control, what does 'key accountability' mean? → Knowing at all times who holds which keys and being able to retrieve them
9. Which credential technology is considered most vulnerable to cloning attacks in commercial access control? → 125 kHz proximity (Prox) cards
10. Which practice best protects a locksmith business from false accusations after completing a residential lock-out? → Photograph the door and lock area before and after service and retain signed authorization
11. A door latch bolt is not retracting fully when the knob is turned. What is the MOST likely cause? → Broken return spring inside the latch mechanism
12. What is the primary advantage of a rotating-element (RE) security pin in a pin tumbler cylinder? → It rotates freely, resisting the tactile feedback a picker uses to detect binding
13. How is key control related to security? → It helps track key usage and prevent unauthorized duplication
14. What is the purpose of biometric security systems? → To verify identity using physical traits
15. What should be done if a key becomes stuck in the lock? → Lubricate the lock mechanism
16. In physical security, what is a 'security vulnerability'? → A weakness that could be exploited to gain unauthorized access
17. A hotel guest has locked themselves out and the room uses a key card electronic lock. The locksmith should: → Coordinate with hotel management for an override card or emergency code
18. What is a key management software? → A tool for tracking key usage and access
19. What is the most common material used in lock construction? → Brass or steel
20. What is the purpose of a 'paracentric' keyway design in high-security lock systems? → To make picking more difficult by obstructing the insertion of pick tools into the keyway
21. Which code system uses alphanumeric codes that directly represent the depth and spacing of key cuts? → Direct codes
22. In key system terminology, what is a 'keyway'? → The profile cut into the cylinder plug that accepts a specific key blade shape
23. What does the term 'bitting' refer to in key cutting? → The series of cuts along the key blade that operate the lock
24. What is a common issue with deadbolt locks? → The deadbolt fails to engage properly
25. Which tool category is used to bypass or read automotive immobilizer data directly through the OBD-II port? → Automotive diagnostic programmer (e.g., Autel, Launch, Xhorse VVDI)
26. When installing an electric strike, what is the purpose of the 'fail-safe' vs. 'fail-secure' configuration? → Fail-safe unlocks on power loss; fail-secure locks on power loss
27. A 'door coordinator' is installed on a pair of commercial doors primarily to: → Ensure the inactive door closes before the active door
28. When using an electronic code-cutting machine, a 'zero-out' or calibration procedure is performed to: → Establish a precise reference position so all subsequent cuts are accurately located
29. How often should locks be maintained? → Annually
30. What type of perimeter lighting is generally considered most effective for deterring crime while minimizing energy costs? → Motion-activated LED lighting