Credentials

The state or city license that lets an electrician work independently. Typically earned after about 8,000 supervised hours and a code-based exam.

The top individual electrical license: design, permits and supervision. Usually requires years as a journeyman plus a harder exam.

The business license for selling electrical work, built on a qualifying master plus insurance, bonding and registration.

The state licence to sell and take responsibility for construction work. Every state assembles it differently from the same four parts: competence (exams), documented experience, financial responsibility (bond and insurance), and a named qualifying individual the licence binds to. Scope, thresholds and enforcement vary widely, and a few states barely license general contractors at all.

The state-specific half of contractor licensing, covering licensing law, contracts, lien law, payroll and employment, insurance, bonding, safety duties and financial management. NASCLA's accredited trade exam does not replace it: NASCLA's own candidate bulletin tells candidates they must still take a business and law examination in the state they are applying to.

The state license to run an HVAC business, typically requiring experience proof, exams, insurance and bonding.

The licence to work as a plumber in your own right rather than under supervision, earned through documented supervised hours and a code exam written against the plumbing code your jurisdiction has adopted. There is no national plumbing licence: the issuing authority is a state board in most states, a state health department in Illinois, a city in places like Chicago, and in California there is no individual plumber licence at all.

The senior individual plumbing licence, gated behind a period holding a journeyman licence and a broader exam covering system design and administration. In most licensing jurisdictions a plumbing business operates under a master's licence, which is what makes it the practical bottleneck for starting a shop.

The business licence for plumbing work. Where individual licensing exists it sits on top of a qualifying master; in California it replaces individual licensing entirely, as the CSLB C-36 Plumbing Contractor classification.

ASSE International's Series 5000 Cross-Connection Control Professional Qualifications Standards, the certifications behind testing, repairing, surveying and administering backflow prevention. Training is delivered by ASSE Accredited Schools and the certification is awarded independently of them; every ASSE certification recertifies on a three-year cycle.

ASSE International's Series 6000 Professional Qualifications Standards for piped medical gas and vacuum systems in healthcare facilities. The series deliberately splits the work across separate certifications by role, so that the person who verifies a system is never the person who installed it. Every ASSE certification recertifies on a three-year cycle.

Welder and procedure qualification under ASME Section IX, required for boiler and pressure-vessel work.

The CCO certification family administered by NCCCO: mobile crane operator, rigger, signalperson, and lift director. The operator certification is OSHA-recognized under 29 CFR 1926.1427 and recertified every five years.

Certification for rigging loads and directing crane operations.

NICET's certification family for water-based fire protection systems: a four-level Layout track and a three-level Inspection and Testing track, both referenced in many state fire codes. Three-year recertification.

NICET's four-level fire alarm certification for engineering technicians: exams plus documented work history at every level, personal recommendations at Levels III and IV, a Major Project at Level IV, recertification every three years via continuing professional development.

BICSI's cabling installation ladder: Installer 1 (INST1), Installer 2 Copper (INSTC), Installer 2 Optical Fiber (INSTF), and Technician (TECH). Renewable credentials recertify on a three-year CEC cycle including one BICSI ethics course.

ASE's truck technician certifications, T2 through T8. Recertification every five years keeps them current.

Mandatory state certification for drinking water operators, in sequential grades with exams and continuing education.

Mandatory state certification for wastewater operators, graded like water operator licenses.

Recognition of completed lineworker apprenticeship: the trade's core credential.

State-issued elevator mechanic licenses, required in most states. Patterns vary: some states credit NEIEP or CET completion toward the exam or education requirement (Washington), some require registered-apprentice standing plus approved classroom hours (Massachusetts), and some run statewide licensing through the labor department under an elevator safety act (New York).

State roofing contractor licenses, strict in some states and absent in others.

Testing, adjusting and balancing certification for individuals. Three separate bodies certify in this discipline: TABB (issued through the International Certification Board), NEBB and AABC. Each runs its own two-tier ladder and none of them recognise each other's cards.

State-fragmented licensing for power-limited work: limited energy electrician/technician licenses (WA 06, OR LEA/LEB), low-voltage contractor classifications (CA C-7), and separate security/alarm licensing regimes (TX DPS Private Security, FL Alarm System Contractor I/II).

The state-issued contractor license that legally authorizes solar installation work; scope, exams and overlap with electrical licenses vary by state.

WPI's voluntary international designation for water and wastewater operators: one uniform standard across four disciplines, four levels each, built to travel between jurisdictions where state certifications do not.

The state contractor license classifications that cover masonry and concrete work (for example CSLB C-29 masonry and C-8 concrete in California). Jurisdiction-dependent; requirements live on the per-state rows.

NCCER's carpentry assessments and journey-level credentials, earned by passing a written knowledge assessment plus an observed Performance Verification. Employer-recognised, never a license.

The state business license that actually gates paid carpentry work. California issues it as the C-5 Framing and Rough Carpentry classification; Oregon requires a CCB license for any construction activity including carpentry; many states require none at all below a dollar threshold.

NRCA's certification program for individual roofing workers, earned by system type through an online eligibility exam plus a hands-on performance assessment.

Recognition of a completed ironworker apprenticeship: the trade's core credential. Ironworking is not a licensed trade, so this is a completion credential rather than a government license.

The National Board's inspector commissions, issued to individuals who meet education, experience, employment and examination requirements under NB-263 (RCI-1). The commission cannot be held freelance: the holder must be employed by a jurisdiction or an accredited inspection organization.

ASME's certification of a manufacturer's or assembler's quality control system, which entitles the organization to apply the ASME Certification Mark with a designator. It certifies a company, not a person, and it is not a welding qualification.

The license to operate a boiler plant, issued by a state or a city and never by ASME or the National Board. Thresholds, class ladders, exams and renewal cycles differ by jurisdiction: New York City licenses high-pressure boiler operating engineers, Minnesota runs a statewide Special/Second/First/Chief ladder, and Chicago licenses stationary engineers municipally.

A shared trade examination that 20 state licensing agencies across 16 states and the US Virgin Islands accept in place of their own trade exam. Passing it is not a licence and licenses you nowhere: you still apply to each state board, meet its experience, financial and bonding rules, and sit its own business and law exam.

The federal certification legally required to handle refrigerants. Four types, administered by EPA-approved organizations. Never expires.

NATE's flagship HVAC certification: five 30-question exams across the technician skill set.

BCSP's site-level construction safety certification, reachable on experience alone: three years in construction safety with at least 35% of duties in safety, health and environment, and no education requirement. Accredited by ANAB to ISO/IEC 17024 and maintained on a five-year recertification cycle.

BCSP's senior generalist certification for people who run safety programmes rather than sites. Requires a bachelor's degree in any field, four years of professional safety experience, and an existing BCSP Qualified Credential such as the ASP. Accredited by ANAB to ISO/IEC 17024 since 2003, the first SH&E certification to be so accredited.

A welding performance qualification held in AWS's national registry, so it travels between employers.

The Certified Welding Inspector credential: three-part exam, experience requirements, nine-year recertification cycle.

ACI's certification for testing fresh concrete in the field, required on much public work. Five-year validity.

ACI certification for concrete flatwork finishing.

Registered Communications Distribution Designer, BICSI's ICT design credential. Eligibility (v15): two years of ICT design experience plus a current BICSI TECH/RTPM/DCDC/OSP credential, OR two years of design experience plus two years of ICT higher education, OR five years of verifiable ICT experience. Recertifies every three years with 45 CECs, one BICSI ethics course, and one qualifying conference credit.

The gold-standard solar certification: PV installation professionals with verified training and experience.

NABCEP's entry credential demonstrating solar fundamentals.

The EPA certification for motor vehicle air conditioning refrigerant work.

NAEC Certification Board credential earned through a two-level, roughly four-year education track (Level 1, 11 units, leads to the AET certificate; Level 2, 8 units, completes CET). ANAB-accredited; requires an employer sponsor with a CET Supervisor and 10 contact hours of continuing education annually.

Inspector designation certified against the ASME QEI-1 Standard for the Qualification of Elevator Inspectors by ANAB-accredited bodies, including NAESA International and NAEC. Requires documented training and at least one year of experience performing or witnessing A17.1/CSA B44 inspections and tests, a proctored exam, and about 10 hours (1.0 CEU) of continuing education per renewal.

NABCEP board certification for PV system designers: 12 design project credits, OSHA 10, and 24 hours of advanced training including 6 NEC hours.

NABCEP board certification for hands-on installers: 6 project credits in a decision-making role, OSHA 10, and 24 hours of advanced training including 6 NEC hours.

NABCEP board certification for commissioning, operations and maintenance: 12 project credits, OSHA 30, and 24 hours of advanced training including 6 NEC hours.

NABCEP board certification for solar sales professionals, qualified through verifiable sales credits with at least half of proposals sold and installed.

NABCEP board certification for battery storage installers: OSHA 30, 58 hours of advanced ES training, and installation project credits measured in kWh.

NABCEP certification for PV inspectors with no entry prerequisites: a 45-question exam and 8 NEC continuing-education hours per 3-year cycle.

NICET's four-level certification for technicians who design, install and maintain special hazards suppression systems (clean agent, CO2, foam and other non-water agents). Three-year recertification via CPD.

School-level ASE certification for students in the medium-heavy truck series. No work experience required; valid two years and not renewable, then the professional T series takes over.

The qualification that lets a technician perform and sign federal annual (periodic) inspections. No federal card or exam exists; the motor carrier qualifies the inspector and retains the evidence.

ACI lab certification for compressive and flexural strength testing of hardened concrete (ASTM C39, C78, C617, C1231). Written plus performance exam, no experience prerequisite, valid five years.

ACI certification for sampling and gradation testing of aggregates (AASHTO R 90/ASTM D75, R 76/C702, T 11/C117, T 27/C136). Open-book written exam plus performance exam, no experience prerequisite.

The certificate issued when you finish a DOL-registered or state-registered apprenticeship. It is the portable, nationally recognised credential a carpenter actually earns, and it is not a license to work.

SMRP's professional credential for maintenance, reliability and physical asset management, tested across the five pillars of the SMRP Body of Knowledge. Open to anyone: no education or experience prerequisite.

SMRP's technician-level credential for multi-skilled maintenance technicians, tested across four hands-on domains from preventive work to corrective repair. No education or experience prerequisite.

An organizational accreditation, not a personal one: the National Board authorizes a repair firm to repair and alter pressure-retaining items and to apply the R symbol stamp. It is held by the shop, never by the welder.

ASME accreditation for the agencies that inspect ASME Certificate Holders. Like the certificates it polices, it accredits an organization rather than an individual inspector.

Completion of the four-year Boilermakers National Apprenticeship Program: 6,000 field construction hours of on-the-job training and 576 hours of related classroom instruction, applied for through a local Lodge.

BCSP's mid-level safety certification and the most common qualifying credential on the route to the CSP. Requires a bachelor's degree in any field or a qualifying associate degree, plus one year of professional-level safety experience.

BCSP's certification for supervisors, foremen and tradespeople whose safety duties are collateral to their main job. Thirty hours of safety training plus one of four experience routes, with no percentage-of-time-on-safety requirement.

BCSP's management-focused certification, requiring ten years of experience with at least 35% of tasks in safety management and no formal education. Renamed from Safety Management Specialist (SMS) in March 2025 with requirements and accreditation unchanged.

The entry tier of the AWS inspection ladder: a CAWI performs inspections alongside a CWI or SCWI, who determines final acceptance.

The top tier of the AWS inspection ladder, for inspectors who also manage CWIs and CAWIs, requiring prior CWI standing, long documented experience and four endorsement exams.

An AWS certification for shop leads and supervisors, aimed at running productive welding operations rather than inspecting or making welds.

An AWS certification for professionals directing welder training and classroom instruction.

An AWS certification validating the ability to interpret radiographic film for welding indications, and one of the routes that satisfies CWI nine-year recertification.

An AWS certification for robotic and automated arc welding personnel, measuring capability working with codes, standards and specifications.

Ten hours of voluntary hazard-awareness training in OSHA's Outreach Training Program, delivered by an OSHA-authorized trainer or online provider. OSHA states plainly that no Outreach course is a certification and that the training does not meet the requirements of any OSHA standard.

Thirty hours of voluntary Outreach training aimed at supervisors and anyone responsible for other workers' exposure. Same programme and same authorized-provider rules as the 10-hour card, and equally not a certification and not a substitute for standard-specific training.

Industry-specific 10-hour safety course created under OSHA Strategic Partnership #325 for electric transmission and distribution construction; delivered through partner AJATCs with completion cards. Distinct from the general OSHA 10 Outreach card.

State-issued driver license under FMCSA standards. A driver credential adjacent to the trade: many shops need technicians who can legally road-test the trucks they repair.

The NYC Department of Buildings license required to operate cranes and hoisting machines in New York City, layered on top of national certification: Class A (booms under 200 ft), Class B (all cranes), and Class C1/C2/C3 (smaller machines).

A Texas licence endorsement, not a standalone certification: Texas carries medical gas authorisation on the plumbing licence itself rather than relying on the ASSE card alone.

Texas's backflow and cross-connection endorsement, carried on the plumbing licence.

A restricted-scope plumbing licence that sits below journeyman. Texas is the anchor example; the tier does not exist in every state.