- What Is a TX-RW?
- Who Issues the License and Who Administers the Exam
- Exam Format: Questions, Time, and Scoring
- The 10 Domains a TX-RW Candidate Must Master
- Eligibility: Hours, Supervision, and Application
- Open-Book Rules: What You Can and Cannot Bring
- Fees, Renewal, and Continuing Education
- Who Hires Someone With a TX-RW
- Building a Domain-Weighted Prep Schedule
- Frequently Asked Questions
- TX-RW is the Texas Residential Wireman Electrician License Exam, administered by PSI for TDLR.
- The exam has 80 scored questions plus 5 unscored pilot items, given in 4 hours 20 minutes.
- Passing requires a 70% score; the exam is open-book with strict tab and annotation rules.
- License scope is limited to single-family and multifamily dwellings of four stories or fewer.
What Is a TX-RW?
The TX-RW is the Texas Residential Wireman Electrician License Exam, the state-administered test that Texas requires before a person can legally hold a Residential Wireman license under the Texas Department of Licensing and Regulation (TDLR). It is not a national certification, a manufacturer credential, or a voluntary skills badge - it is a regulatory exam tied directly to a state license that permits electrical work on residential structures.
Unlike broader journeyman or master electrician licenses, the Residential Wireman scope is intentionally narrow: it covers wiring, service, and equipment work on single-family and multifamily dwellings that do not exceed four stories. If you plan on commercial or industrial work, this is not the credential you need - but for residential contractors, remodelers, and home-service electricians, it is the standard entry point into licensed solo work in Texas.
For a deeper breakdown of the acronym itself and how it differs from similarly-named credentials elsewhere, see TX-RW Meaning and What Does TX-RW Stand For?.
Who Issues the License and Who Administers the Exam
TDLR is the state agency that owns the Residential Wireman license - it sets eligibility rules, approves applications, and issues the license itself. The actual examination, however, is delivered by PSI Services LLC at computer-based testing centers under a bulletin that TDLR and PSI jointly maintain. That bulletin governs everything from what you can bring into the testing room to which edition of the NEC the questions reference.
This two-party structure matters practically: your application and experience verification go through TDLR, but your test scheduling, exam-day rules, and score reporting go through PSI. Confusing the two can cause avoidable delays, so candidates should read both agencies' materials rather than relying on secondhand summaries.
Exam Format: Questions, Time, and Scoring
The TX-RW is a computer-based, multiple-choice examination. It consists of 80 scored questions delivered in 240 minutes, plus five additional unscored (pilot) questions with 20 extra minutes allotted. In total, candidates sit for 85 questions across four hours and twenty minutes. The unscored questions are indistinguishable from scored ones during the test, so every question should be treated as if it counts.
A passing score is 70%. The exam is available in both English and Spanish, which is worth noting when scheduling since not every test center may offer both language options on every date.
Key Takeaway
Because pilot questions are mixed in unmarked, pace yourself for all 85 items rather than trying to identify which ones "don't count." You won't be able to tell.
For a full explanation of exactly what "passing" means numerically and how the 70% threshold interacts with the 80 scored items, see TX-RW Passing Score 2026: Exactly What You Need to Pass.
The 10 Domains a TX-RW Candidate Must Master
TDLR and PSI organize the scored content into ten domains with fixed question counts. Knowing the weight of each domain lets you allocate study time proportionally instead of spreading effort evenly across topics that don't carry equal exam weight.
| Domain | Topic | 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 dominate the scored total: Electrical Services, Service Equipment, and Separately Derived Systems is the largest single domain at 16 questions, followed by Branch Circuit Calculations and Conductors at 14, and Electrical Equipment and Devices at 12. Together these three domains account for a substantial share of the entire exam - more than the remaining seven domains combined in several cases.
Electrical Services, Service Equipment, and Separately Derived Systems
This is the highest-weighted domain, so candidates should be fluent in service sizing, grounding and bonding for separately derived systems, and equipment rating rules.
- Service entrance conductor sizing and clearances
- Grounding electrode system requirements
- Separately derived system bonding distinctions
Branch Circuit Calculations and Conductors
Expect direct calculation questions using standard methods and copper conductors unless a question explicitly states otherwise.
- Conductor ampacity and derating
- Branch circuit load calculations for dwelling units
- Voltage drop and conductor sizing basics
The two lightest domains - Motors and Generators, and Renewable Energy Technologies - contribute only two questions each, so while you shouldn't ignore them, they should not consume study time proportional to the heavier domains. A full walkthrough of every domain, with the reasoning behind each weight, is available in TX-RW Exam Domains 2026: Complete Guide to All 10 Content Areas.
Eligibility: Hours, Supervision, and Application
You cannot simply register for the TX-RW the way you might sign up for a generic certification exam. TDLR requires candidates to first qualify through one of two paths:
- 4,000 documented on-the-job hours supervised by a Texas-licensed Master Electrician or Residential Wireman, with separate signed experience verification from each supervisor you worked under, or
- Completion of a TDLR-approved career and technology education program.
Once your application is approved by TDLR, you become eligible to schedule the exam through PSI. Everything - application approval, scheduling, and passing the exam - must be completed within one year of your application date, though you are permitted repeat attempts within that eligibility window if you don't pass on the first try.
For the complete eligibility checklist, including how supervised hours are typically documented, read TX-RW Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Open-Book Rules: What You Can and Cannot Bring
The TX-RW is an open-book exam, but "open book" comes with specific constraints that trip up unprepared candidates. You are allowed to bring a softbound NEC with notes, highlighting, or underlining - but only if that annotation was completed before you arrive at the testing center. No marking is permitted during the exam itself; PSI provides an electronic notepad for scratch work instead.
Tabs are another frequent stumbling point. Only permanent index tabs manufactured or provided by the NEC publisher are allowed. Homemade tabs, third-party sticky tabs, movable tabs, added loose sheets, the NEC Handbook (as opposed to the code book itself), and any spiral-bound, ring-bound, or loose-leaf version of the code are all prohibited.
- Allowed: softbound NEC, publisher-made permanent tabs, pre-exam highlighting/underlining/notes
- Not allowed: homemade or third-party tabs, movable tabs, added sheets, NEC Handbook, spiral/ring-bound books, in-test marking
Key Takeaway
Prepare your NEC book weeks before test day - tabbing, highlighting, and note-taking must be finished in advance since nothing can be added once testing begins.
The exam also defaults to copper conductors and standard calculation methods unless a question specifically instructs you to consider an alternate material, code exception, or optional calculation method. Reading each question carefully for those directional cues is essential, since assuming an exception applies when it wasn't stated is a common wrong-answer trap.
Fees, Renewal, and Continuing Education
Budgeting for the TX-RW involves more than the exam fee alone. The examination itself costs $64 per attempt, charged separately from the $20 initial license application fee TDLR collects. If you don't pass, you'll need to pay the exam fee again for each retake attempt.
Once licensed, Residential Wiremen renew annually for $20, provided they complete four TDLR-approved continuing education hours covering the NEC, Texas electrician law and rules, and NFPA 70E safety topics. This annual cadence means the license requires ongoing engagement with code updates, not a one-time exam and done.
For a full cost breakdown across application, exam, retakes, and renewal, see TX-RW Certification Cost 2026: Complete Pricing Breakdown, and for scheduling windows around the code-edition change, check TX-RW Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Who Hires Someone With a TX-RW
Because the Residential Wireman scope is capped at single-family and multifamily dwellings of four stories or fewer, the license is most valuable to people working in residential construction and service work rather than commercial or industrial electrical fields. Typical employers and work arrangements include:
- Residential electrical contracting companies handling new home builds
- Remodeling and renovation contractors needing licensed wiring work
- Home service and repair companies (panel upgrades, rewires, troubleshooting)
- Multifamily property developers and maintenance operations, within the four-story limit
- Independent residential electricians operating under their own license
Because the license doesn't cover commercial or high-rise multifamily work, candidates weighing whether to pursue it versus a broader license should think about long-term career direction. A dedicated breakdown of earning potential and career paths tied to this license is covered in TX-RW Salary Guide 2026: Complete Earnings Analysis and TX-RW Jobs, while a broader value discussion is in Is the TX-RW Certification Worth It? Complete ROI Analysis 2026.
Building a Domain-Weighted Prep Schedule
Generic study advice - flashcards, timed drills, spaced repetition - only helps if it's pointed at the right targets. Given the fixed domain weights, the smartest schedule spends the most calendar time on Domain 2 (Services and Service Equipment), Domain 4 (Branch Circuit Calculations), and Domain 6 (Equipment and Devices), since together they represent the bulk of the scored questions.
Heaviest Domains First
- Study Domain 2: services, service equipment, separately derived systems
- Study Domain 4: branch circuit calculations and conductor sizing
- Practice tabbing your NEC book for these sections now, since tabs must be set before exam day
Mid-Weight Domains
- Study Domain 6: electrical equipment and devices
- Study Domain 5: wiring methods and materials
- Study Domain 1: definitions, calculations, theory, and plans
Remaining Domains
- Cover Domain 3 (feeders) and Domain 9 (special occupancies)
- Review light-weight Domains 7, 8, and 10 briefly - only 2 questions each
Simulated Testing
- Take full-length timed practice exams matching the 85-question, 4-hour-20-minute format
- Finalize NEC annotations and confirm permanent tabs are publisher-made
For a structured week-by-week plan built specifically around these weights, see TX-RW Study Guide 2026: How to Pass on Your First Attempt. If you're trying to gauge realistic difficulty before committing to a timeline, How Hard Is the TX-RW Exam? Complete Difficulty Guide 2026 and TX-RW Pass Rate 2026: What the Data Shows walk through what the exam-attempt data actually shows. You can also start running timed practice questions right now at the TX-RW practice test platform to see which domains need the most attention.
Key Takeaway
Don't split study time evenly across all 10 domains - the top three domains alone account for 42 of the 80 scored questions.
Frequently Asked Questions
No. The TX-RW qualifies you specifically for the Residential Wireman license, which is limited to single-family and multifamily dwellings of four stories or fewer. It is a distinct license path from journeyman or master electrician credentials in Texas.
There are 80 scored questions given in 240 minutes, plus 5 unscored questions with an additional 20 minutes, for a total of 85 questions across 4 hours and 20 minutes.
Yes, but it must be a softbound NEC with only permanent, publisher-made index tabs. Notes, highlighting, and underlining must be completed before the exam; homemade tabs, the NEC Handbook, and spiral or ring-bound books are prohibited.
A passing score is 70%. See TX-RW Passing Score 2026 for how that threshold applies to the scored question count.
You need 4,000 documented on-the-job hours supervised by a Texas-licensed Master Electrician or Residential Wireman (with signed verification from each supervisor), or completion of a TDLR-approved career and technology education program, followed by TDLR application approval.