The Quick Answer
If you already have or are getting the Series 7, take the Series 66. It’s one exam instead of two, and it covers both state agent registration and investment adviser registration.
If you do not have the Series 7 and don’t plan to get it, take the Series 65. It’s standalone with no prerequisites.
Side-by-Side Comparison
| Feature | Series 66 | Series 65 |
|---|---|---|
| Full Name | Uniform Combined State Law Exam | Uniform Investment Adviser Law Exam |
| Questions | 100 scored + 10 unscored | 130 scored + 10 unscored |
| Time Limit | 150 minutes | 180 minutes |
| Passing Score | 73 / 100 (73%) | 92 / 130 (~71%) |
| Exam Fee | $177 | $187 |
| Prerequisites | Series 7 (co-requisite) | None |
| Qualifies You As | Securities agent + IAR (dual) | IAR only |
| Equivalent To | Series 63 + Series 65 combined | Series 65 only |
What Each Exam Tests
The Series 65 goes deeper on products and economics. Because it assumes no Series 7, it includes more questions on investment products, economic theory, and quantitative analysis.
The Series 66 is heavier on regulatory procedure. It assumes you learned products through the Series 7, so it focuses on the Uniform Securities Act, registration, administrator powers, exemptions, and the fiduciary standard. Section IV is 45% of the exam.
Three Career Paths, Three Answers
Path 1: BD + advisory dual role. Take the Series 7 + Series 66. Most common for financial advisors at wirehouses and regional BDs.
Path 2: Fee-only investment advice, no transactions. Take the Series 65 alone. For fee-only RIA firms and independent planners.
Path 3: Already passed the Series 63. Take the Series 65. The 66 would duplicate your 63 coverage.
Which Is Harder?
If you’ve recently passed the Series 7, the Series 66 is generally easier because you already know investment products. The new material (state law, fiduciary duty) is manageable.
If you’re coming in fresh, the Series 65 covers more total content but has a slightly lower passing threshold (~71% vs 73%).
Study Time Comparison
| Scenario | Series 66 | Series 65 |
|---|---|---|
| Recently passed Series 7 | 40–60 hours | 60–80 hours |
| Series 7 was months ago | 60–80 hours | 70–90 hours |
| No prior securities exams | N/A (need S7) | 80–120 hours |
The Bottom Line
Your firm will usually tell you which to take. If they don’t: have the Series 7 → Series 66. Going fee-only → Series 65. Already have the 63 → Series 65.
Either way, the free Series 66 course and practice exams can help you prepare — much of the content overlaps between both exams.