- What TX-RW Actually Means
- Who Issues the License and Who Runs the Exam
- Exam Format, Fees, and Scoring
- What the Ten Domains Actually Cover
- The Open-Book NEC Rules
- Qualifying to Sit for the Exam
- Who Holds This License on the Job
- Mapping Study Time to the Name Behind the Letters
- Frequently Asked Questions
- TX-RW means Texas Residential Wireman Electrician License Exam, administered by TDLR through PSI Services LLC.
- The exam has 80 scored questions plus 5 unscored pilot questions in a four-hour-20-minute window.
- Passing requires 70%, and it is offered in both English and Spanish.
- Electrical Services, Service Equipment, and Separately Derived Systems carries the heaviest weight at 16 questions.
What TX-RW Actually Means
TX-RW stands for the Texas Residential Wireman Electrician License Exam - the state examination a candidate must pass to hold a Residential Wireman license issued by the Texas Department of Licensing and Regulation (TDLR). The name itself is descriptive: "TX" identifies the jurisdiction (Texas), and "Residential Wireman" identifies the license scope, which is limited to wiring work in dwellings rather than commercial, industrial, or high-rise construction.
This distinction matters because several unrelated credentials in other industries also use the shorthand "TX-RW." None of those apply here. On this site, and throughout this article, TX-RW refers exclusively to the Texas electrical licensing exam described above - nothing else.
Who Issues the License and Who Runs the Exam
TDLR is the state agency that owns the Residential Wireman license program, sets eligibility rules, and approves applications. The actual exam delivery, scheduling, and score reporting is handled by PSI Services LLC, a third-party testing vendor that runs the computer-based test at approved test centers.
Before you can schedule a seat with PSI, TDLR has to approve your application. This sequencing trips people up: you cannot simply register and test whenever you like. Approval comes first, then scheduling, then the exam itself. Once your application is approved, you generally have one year to complete all licensing requirements, and you're allowed to retake the exam during that eligibility window if needed. For a full walkthrough of what TDLR expects before you reach that point, see TX-RW Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Exam Format, Fees, and Scoring
The TX-RW exam is a computer-based, multiple-choice test consisting of 80 scored questions delivered in 240 minutes, plus five additional unscored (pilot) questions with an extra 20 minutes tacked on. In total, candidates sit for 85 questions across four hours and 20 minutes, though only the 80 scored items count toward the result.
- Exam fee: $64 per attempt
- Initial license application fee: $20 (separate from the exam fee)
- Passing score: 70%
- Language options: English and Spanish
Because the fee is charged per attempt, a failed exam means paying $64 again to retest - a detail worth planning around. If you want a granular breakdown of every fee involved from application through renewal, TX-RW Certification Cost 2026: Complete Pricing Breakdown covers the full picture. For a closer look at what 70% actually requires in terms of correct answers and domain performance, see TX-RW Passing Score 2026: Exactly What You Need to Pass.
Key Takeaway
You're not just answering 80 questions - you're managing a 4-hour-20-minute session that includes unscored items you can't identify. Pace yourself as if every question counts, because you can't tell which ones don't.
What the Ten Domains Actually Cover
The "Residential Wireman" part of TX-RW isn't just a license title - it defines the ten content domains the exam draws from. Question counts are fixed by the official blueprint, so some domains matter far more than others on test day.
| Domain | Scored Questions |
|---|---|
| 1. Definitions, Calculations, Theory, and Plans | 8 |
| 2. Electrical Services, Service Equipment, and Separately Derived Systems | 16 |
| 3. Electrical Feeders | 7 |
| 4. Branch Circuit Calculations and Conductors | 14 |
| 5. Electrical Wiring Methods and Electrical Materials | 10 |
| 6. Electrical Equipment and Devices | 12 |
| 7. Motors and Generators | 2 |
| 8. Electrical Control Devices and Disconnecting Means | 2 |
| 9. Special Occupancies, Equipment, and Conditions | 7 |
| 10. Renewable Energy Technologies | 2 |
Three domains - Electrical Services/Service Equipment/Separately Derived Systems (16), Branch Circuit Calculations and Conductors (14), and Electrical Equipment and Devices (12) - together make up more than half of the scored exam. Domains 7, 8, and 10 each contribute only two questions apiece, so they deserve review but shouldn't consume disproportionate study time.
Electrical Services, Service Equipment, and Separately Derived Systems
The single heaviest domain on the exam at 16 questions. Candidates need to be comfortable with service entrance conductors, grounding and bonding at the service, and how separately derived systems (like generators or certain transformer setups) are grounded differently from a standard utility service.
- Expect scenario-based questions referencing NEC service and grounding articles
Branch Circuit Calculations and Conductors
At 14 questions, this domain tests load calculations, conductor sizing, ampacity adjustments, and voltage drop concepts as they apply to dwelling branch circuits - not commercial feeders.
- Practice standard calculation methods first; code exceptions only apply when a question explicitly says so
For a domain-by-domain study breakdown with more depth than this overview, see TX-RW Exam Domains 2026: Complete Guide to All 10 Content Areas.
The Open-Book NEC Rules
Unlike many licensing exams, TX-RW is open book - but the rules around what "open book" means are strict, and violating them can disqualify you on the spot.
- You must bring your own softbound NEC code book
- Notes, highlighting, and underlining completed before the exam are allowed
- Index tabs must be manufactured or provided by the NEC publisher - homemade, third-party, or movable tabs are prohibited
- Added sheets, the NEC Handbook, and loose-leaf, spiral-bound, or ring-bound books are not permitted
- You cannot mark up the book during the exam itself; a proctor-provided electronic notepad is available for scratch work instead
Also worth remembering: unless a question specifically instructs otherwise, assume copper conductors and standard calculation methods. Code exceptions and optional calculation methods only come into play when the question explicitly directs you there - a subtlety that trips up candidates who over-apply exceptions from memory.
Qualifying to Sit for the Exam
Before you can even schedule the TX-RW exam, TDLR requires proof of hands-on experience. You'll need one of the following:
- 4,000 documented on-the-job hours supervised by a Texas-licensed Master Electrician or Residential Wireman, or
- Completion of a TDLR-approved career and technology education program
Each supervisor you worked under must independently sign off on your experience verification - you can't combine hours from multiple supervisors into a single form. Once TDLR approves your application, the clock starts on a one-year window to complete every remaining requirement, including passing the exam itself. If you fail on your first attempt, you can retest, paying the $64 fee again, as long as you're still within that eligibility period.
The full documentation process, including what counts as acceptable proof of hours, is detailed in TX-RW Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Who Holds This License on the Job
A Residential Wireman license authorizes work on single-family and multifamily dwellings not exceeding four stories. That scope shapes who pursues the credential: electricians working primarily in home construction, remodeling, and residential service calls rather than commercial or industrial settings.
Because the license is scoped this narrowly, it's common for residential electrical contractors, home builders, and property-focused electrical firms in Texas to specifically seek out RW-licensed workers rather than a broader journeyman credential. If you're weighing whether pursuing this license fits your career direction, Is the TX-RW Certification Worth It? Complete ROI Analysis 2026 and TX-RW Salary Guide 2026: Complete Earnings Analysis go deeper into that decision. For where employers are actively looking for RW-licensed electricians, see TX-RW Jobs.
Once licensed, renewal is annual: $20 plus four TDLR-approved continuing education hours covering the NEC, Texas electrician law and rules, and NFPA 70E safety topics. This keeps license holders current on code changes like the NEC 2026 transition mentioned above.
Mapping Study Time to the Name Behind the Letters
Because "Residential Wireman" defines the scope of every domain, the most efficient prep plan works backward from the blueprint rather than studying the entire NEC cover to cover. Given that three domains account for 42 of the 80 scored questions, allocate study weeks accordingly rather than spreading time evenly across all ten.
Foundations
- Domain 1: Definitions, Calculations, Theory, and Plans (8 questions)
- Set up your NEC index tabs correctly, since improvised tabs aren't allowed on exam day
Heaviest-Weighted Domain
- Domain 2: Electrical Services, Service Equipment, and Separately Derived Systems (16 questions)
- Drill grounding and bonding scenarios specific to dwellings
Calculations Focus
- Domain 4: Branch Circuit Calculations and Conductors (14 questions)
- Practice standard calculation methods before touching optional methods
Equipment and Wiring Methods
- Domain 6: Electrical Equipment and Devices (12 questions)
- Domain 5: Electrical Wiring Methods and Electrical Materials (10 questions)
Remaining Domains and Timed Practice
- Domains 3, 9, 7, 8, and 10 (7, 7, 2, 2, 2 questions)
- Full-length timed practice sessions under open-book conditions
For a structured week-by-week plan built specifically around this weighting, see TX-RW Study Guide 2026: How to Pass on Your First Attempt. And if you're still gauging how much prep time you personally need, How Hard Is the TX-RW Exam? Complete Difficulty Guide 2026 and TX-RW Pass Rate 2026: What the Data Shows put real exam-attempt outcomes in context. You can also run through timed, domain-weighted questions on our TX-RW practice test platform to see how your pacing holds up across a full 240-minute session.
Frequently Asked Questions
TX-RW stands for the Texas Residential Wireman Electrician License Exam, the TDLR-regulated test required to obtain a Residential Wireman electrician license in Texas.
No. The Residential Wireman license is scoped specifically to single-family and multifamily dwellings not exceeding four stories, which is narrower than a general journeyman electrician credential.
There are 80 scored questions plus 5 unscored questions, for 85 total, delivered across four hours and 20 minutes.
Yes, but it must be a softbound NEC with permanent, publisher-made tabs and any pre-existing notes or highlighting. Loose-leaf, spiral-bound, ring-bound books, added sheets, and the NEC Handbook are not allowed.
You can retest by paying the $64 exam fee again, provided you're still within the one-year eligibility window that starts after TDLR approves your application.
Understanding what TX-RW means - down to its exact domains, fee structure, and scope of practice - is the foundation for building a realistic prep plan. From here, explore the domain guide, study guide, and practice platform linked throughout this article, or start with What Is TX-RW? for a broader orientation before diving into exam-specific prep on the main practice test site.