Best free resources for ASO prep in 2026 — compiled list
I've been compiling resources as I study for my ASO - Armed Security Officer Certification certification and figured I'd share what I've found. All free unless noted.
Practice Tests:
- PracticeTestGeeks — most comprehensive collection I've found, good question explanations, covers ASO - Armed Security Officer Certification, SIA - Security Industry Authority Door Supervisor, and SSO - Ship Security Officer. Free.
- Official practice materials from the certifying body — usually 1 free sample exam, worth doing even though it's short
Study Materials:
- The official ASO exam handbook / candidate guide (PDF, free from the certifying body's website)
- YouTube — search for "ASO exam prep" — there are surprisingly good free video reviews for most security services certifications
- Reddit r/certifications — people post their exam experiences and tips regularly
Paid (worth it if budget allows):
- Official study guides run $30-80 for most security services certifications — worth it if your exam has lots of specific factual content
- Some certifying bodies offer prep courses — check if your employer covers it (many do for required certifications)
What resources have others found useful for security services exams? I'll add them to this list.
Great list. I'd add: LinkedIn Learning has some security services-related courses that overlap with cert content, and if you have a library card many libraries give free access to it. Also check if your local library has access to O'Reilly or similar — tons of technical content there.
The official candidate guide is something a lot of people skip but it literally tells you the topic weighting and domain breakdown. It's the roadmap for your study plan. Never skip it.
For ASO - Armed Security Officer Certification specifically, I found the PracticeTestGeeks explanations were detailed enough that I didn't need to buy a separate study guide. The combination of doing the practice questions + reading every explanation (for both right and wrong answers) covered most of the content I needed.