- The published passing score is 70 or higher on a scaled score, not 70 raw answers out of 75.
- Detective Practices carries 40 of 75 questions - more than the other two domains combined.
- You have 90 minutes for 75 single-best-answer questions, roughly 72 seconds per item.
- IDFPR approval must precede Continental Testing Services registration; there is no walk-in path.
The Passing Score: 70, Not "70 Out of 75"
The single most misunderstood number tied to the Illinois Private Detective License Exam is the passing score itself. Continental Testing Services (CTS), which administers this standalone examination for profession 115 under the Illinois Department of Financial and Professional Regulation (IDFPR), publishes a passing score of 70 or higher. That number is a scaled score, not a raw count of correct answers out of the 75 questions on the test.
This distinction matters because candidates routinely try to calculate "how many questions I can miss" using simple arithmetic on 75 items. Since the passing threshold is scaled rather than a literal percentage of raw items answered correctly, that math doesn't map cleanly onto the test. The safest approach is to treat 70 as the target and prepare to comfortably clear it across all three domains, rather than trying to reverse-engineer a specific miss-count.
How the Scaled Score Actually Works
Because CTS reports a scaled score rather than a raw percentage, your results reflect the difficulty and weighting of the specific question set you receive, not simply "number correct divided by 75." Practically speaking, this means:
- You cannot assume that missing 22 or 23 questions automatically fails you, or that missing fewer automatically passes you - the scaling adjusts for item difficulty.
- Guessing on questions you don't know is still better than leaving them blank, since there is no indication of a penalty for incorrect answers beyond simply not earning credit.
- Strong performance across all three domains matters more than "acing" one section and neglecting another, since a weak showing in a heavily weighted area like Detective Practices is harder to offset.
If you want a deeper breakdown of what makes this exam challenging in practice - timing pressure, question phrasing, and how the material is tested - see How Hard Is the IL-PD Exam? Complete Difficulty Guide 2026. For a broader look at outcomes across candidates, IL-PD Pass Rate 2026: What the Data Shows covers what's publicly known about results.
Question Allocation by Domain
The 75-question exam is built from three official sections. Knowing the exact allocation is the single most useful piece of information for deciding where to spend your study hours, because points are not distributed evenly.
| Domain | Questions | Share of Exam |
|---|---|---|
| Domain 1: Federal & State Law | 23 | ~31% |
| Domain 2: Licensing & Practice Requirements | 12 | ~16% |
| Domain 3: Detective Practices | 40 | ~53% |
Domain 3 alone accounts for more than half of the scored questions, and it further divides into three subareas used for constructing the test: Gathering Information (16 questions), Case Management (12 questions), and Analysis, Reporting & Presentation (12 questions). These are subareas within Detective Practices, not separate top-level domains, but they're worth tracking individually when you build practice tests, since each tests a distinct skill set.
Key Takeaway
If you only have time to deeply master one domain before your test date, it should be Detective Practices - it determines more of your scaled score than Federal & State Law and Licensing & Practice Requirements combined.
What Each Domain Demands to Hit 70
Passing isn't just about knowing facts - it's about knowing the right proportion of facts in the right places. Here's what each domain actually tests, based on the official question allocations.
Domain 1: Federal & State Law (23 questions)
This section tests your grasp of the statutory and regulatory framework governing private detective work in Illinois, plus relevant federal law that intersects with investigative activity.
- Scope of authority and legal limits on investigative conduct
- Statutory definitions specific to the Illinois licensing framework
- Federal law provisions that affect information gathering and reporting
Domain 2: Licensing & Practice Requirements (12 questions)
The smallest section by question count, but not one to skip - it covers the administrative backbone of holding and maintaining an Illinois PD license.
- Licensing eligibility rules and application mechanics
- Ongoing obligations tied to maintaining active licensure
- Practice standards that govern day-to-day professional conduct
Domain 3: Detective Practices (40 questions)
The largest domain by far, split into three tested subareas that mirror the actual workflow of an investigation from start to finish.
- Gathering Information (16): surveillance methods, interviewing, records and source development
- Case Management (12): organizing investigations, evidence handling, workflow and file management
- Analysis, Reporting & Presentation (12): synthesizing findings and producing usable, defensible reports
For a subarea-by-subarea study plan built specifically around these three domains, IL-PD Exam Domains 2026: Complete Guide to All 3 Content Areas goes further into what each subarea covers and how to allocate practice questions across it.
Registration, Fees, and Scheduling Mechanics
Passing score aside, you can't sit for the exam at all until the administrative sequence is handled correctly - and the order matters. IDFPR approval has to happen before CTS registration; you cannot register with Continental Testing Services first and sort out eligibility later.
- Apply through IDFPR's CORE system and receive Department approval.
- Register with CTS using your authority-to-sit/examination approval ID.
- Pay the $298 exam fee (separate from any licensing fees).
- Sit for the 75-question, 90-minute exam at the scheduled location.
The current CTS schedule lists an exam date of October 28, 2026 in Hillside, with a CTS registration deadline of October 7, 2026. Because Department approval must precede registration, applicants who wait until close to the registration deadline to start their CORE application risk missing the window entirely. For the full testing calendar and how deadlines stack against each other, see IL-PD Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Eligibility itself has its own requirements independent of the exam content: applicants must be at least 21, and typically must document three of the preceding five years of qualifying full-time investigative employment. An approved bachelor's degree can credit two of those years, an appropriate associate degree can credit one year, and qualifying military law enforcement training may support a separate credit route. You'll also need to submit experience-verification forms and background documentation, and secure $1 million in general liability coverage in your own name before a license can be issued after you pass. The complete eligibility picture, including how the education and experience credits interact, is covered in IL-PD Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Sequencing Your Prep Around the Domain Weights
Generic study techniques like spaced repetition or timed drills only pay off if they're pointed at the right material in the right order. Given that Detective Practices carries 40 of 75 questions, the highest-leverage sequencing is to front-load that domain and treat the other two as focused, shorter review blocks.
Detective Practices - Gathering Information & Case Management
- Drill surveillance, interviewing, and source-development scenarios (16-question subarea)
- Build familiarity with evidence handling and case workflow (12-question subarea)
Detective Practices - Analysis, Reporting & Presentation
- Practice turning raw findings into structured, defensible reports
- Run timed practice sets mixing all three Detective Practices subareas
Federal & State Law
- Work through the 23-question domain's statutory framework and scope-of-authority rules
- Flag anything that overlaps with licensing requirements for later review
Licensing & Practice Requirements + Full Simulation
- Review the 12-question licensing domain's administrative and conduct rules
- Take at least one full 75-question, 90-minute timed simulation
This sequencing isn't a generic template - it's built around the specific 23/12/40 question split and the 16/12/12 subarea breakdown of this exam. A more detailed lesson-by-lesson walkthrough, including which resources to prioritize each week, is in IL-PD Study Guide 2026: How to Pass on Your First Attempt. You can also run through domain-weighted practice questions on our practice test platform to see how your accuracy holds up under the same 90-minute constraint you'll face on test day.
Where Candidates Lose Points on This Exam
A handful of avoidable patterns show up repeatedly among candidates who fall short of 70:
- Under-preparing for Detective Practices relative to its weight. Because it spans three subareas, candidates sometimes study it as loosely as the smaller domains rather than as more than half the test.
- Treating the 90-minute limit as generous. Seventy-five single-best-answer questions in 90 minutes leaves little room for lingering on any one item - pacing practice matters as much as content mastery.
- Skipping the Licensing & Practice Requirements domain. At only 12 questions it's tempting to deprioritize, but missing most of a 12-question domain still drags down your scaled score.
- Registering too close to the CTS deadline. Because Department approval must be granted before CTS registration opens the door, procrastinating on the CORE application can cost you the testing window entirely, not just study time.
- Confusing this exam with the combined detective/security-contractor sitting. That version has a different question count (115) and time limit (120 minutes) - studying for the wrong format wastes prep time.
If you're still deciding whether this credential fits your career plans before committing to the fees and prep time, Is the IL-PD Certification Worth It? Complete ROI Analysis 2026 and IL-PD Salary Guide 2026: Complete Earnings Analysis lay out the bigger picture beyond the exam itself. And once you've passed, remember licensure doesn't end at the exam: individual licenses renew every three years on May 31, renewal fees run $150 per year of the cycle, and license holders must complete eight hours of annual training starting the calendar year after issuance, with records retained to prove it.
FAQ
It's a scaled score, not a literal percentage of the 75 questions answered correctly. CTS scales results, so you shouldn't try to calculate an exact "questions you can miss" number based on simple division.
Detective Practices, since it accounts for 40 of the 75 questions - more than Federal & State Law (23) and Licensing & Practice Requirements (12) combined.
The exam allows 90 minutes for 75 questions, which works out to a little over a minute per question on average - tight enough that timed practice is essential.
IDFPR first. You must receive Department approval through CORE and obtain your authority-to-sit/examination approval ID before Continental Testing Services will register you for a test date.
No. The exam fee is $298 and only covers sitting for the test. The individual license application fee is a separate $500, and costs like fingerprinting and liability insurance are additional.
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