What license does a Delaware plumber need?
Delaware’s state plumbing license is Master Plumber, but not every field worker must personally hold it. The Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners issues master plumber, master HVACR and master restricted HVACR licenses. Review the Delaware DPR board page. Delaware law allows an apprentice, journeyman, mechanic, or other person to provide plumbing services without personally holding that license when the person works under the specified supervision of a master plumber. The supervising master must be the person’s employer or a full-time employee of the same business entity. Read the statutory exemption and its conditions. Other exemptions in the statute may also apply, so this guide does not treat the Master Plumber license as a personal requirement for every worker on every job.
A Delaware Master Plumber may design, install, construct, replace, service, repair, alter or modify the pipes, fixtures and apparatus used to bring water into a building and remove liquid and water-carried wastes. The master plumber may also install and connect gas piping, but specified heating, air-conditioning, refrigeration, ventilation and process systems require the applicable HVACR credential in addition. DPR defines that boundary on the licensure page.
Start with the scope, then choose examination or reciprocity. The broader plumbing-license path explains why an apprenticeship title or out-of-state credential does not automatically map to another state’s license.
Master license, apprenticeship certificate, and separate HVACR scope
DPR’s board page identifies Master Plumber as the plumbing license it issues. The absence of a separate state journeyperson license on that list does not mean every journeyperson or apprentice must personally hold Master Plumber. Section 1807 allows supervised workers in the listed categories to provide plumbing services when the supervising master is their employer or works full time for the same business entity; other statutory exemptions may also apply. Review the worker exemption in Delaware Code. The “journeyman certificate” in the examination instructions is different: DPR says it is issued by a federally approved plumbing apprenticeship program, such as the Delaware Department of Labor. It is evidence for one qualification route, not a separate journeyperson license shown on the board’s license list. See DPR’s Master Plumber instructions.
| Item | What it means in the Delaware process |
|---|---|
| Master Plumber | State plumbing license issued by DPR |
| Journeyman certificate | Completion credential from a federally approved plumbing apprenticeship program |
| Apprenticeship By-Pass Exam | Additional step for an approved applicant without that certificate |
| Master exam | Licensure exam taken after board approval |
| Master HVACR or restricted HVACR | Separate credential required for covered HVACR systems |
A business may also face entity, tax, permit or construction-registration requirements outside this occupational license. Use the Delaware contractor-license guide for that adjacent check.
Two experience routes to the Master Plumber exam
Delaware publishes two examination routes.
With a journeyman certificate: Submit the apprenticeship program Certificate of Completion and proof of at least two years of work under a master licensee after receiving that certificate.
Without a journeyman certificate: Submit proof of at least seven years of work under the supervision of a master licensee. The board reviews the experience; if approved, the applicant may take the Apprenticeship By-Pass Exam. DPR lists both routes and their evidence.
For required experience, DPR directs supervisors to complete the Verification of Employment form. When that form cannot be obtained, the page identifies possible substitutes—W-2 records or an employer/officer affidavit plus an explanation; Schedule C may document self-employment. Acceptance remains at the board’s discretion.
Build the file before opening the application: names and license numbers of supervisors, exact dates, duties, certificate, employment verification, fallback tax records if needed, and an explanation for every gap. Use the experience-verification guide to make the chronology auditable.
DELPROS, board review, and exams
All applications are submitted through DELPROS. DPR says an application started there must be submitted within six months or the applicant must restart it. Read the DELPROS and attachment instructions.
For the no-certificate route, board approval of the experience comes before the Apprenticeship By-Pass Exam. After passing that exam with at least 70%, the result must reach the board. When the board approves the applicant to sit for the Master exam, it sends a candidate information packet.
Use this sequence:
- Create the DELPROS account and select Master Plumber.
- Upload applicant-supplied documents and arrange third-party license or employment verification where required.
- Monitor application status and board requests.
- If using the seven-year route, wait for board approval before scheduling the bypass exam.
- Ensure passing bypass results reach the board.
- Wait for approval and the Master-exam candidate packet.
- Follow the current packet for scheduling, references, format and payment.
Do not rely on an old vendor name, bulletin or exam rule; the board-issued packet is the current instruction set for that approved applicant.
Fees and realistic timing
Delaware’s fee schedule lists the Plumber application fee at $173 and says processing fees are non-refundable. It does not post a fixed renewal amount; licensees are notified of the renewal fee at renewal. A late renewal requires an additional fee equal to 50% of the renewal fee. Check the current DPR fee schedule before paying.
Master Plumber licenses renew biennially, with a renewal form, the appropriate fee, and proof that the licensee met any continuing-education requirements established by the board. Read the current Delaware plumbing statute.
The board says its updated Regulation 5 clarifies the continuing-education requirements that take effect for the 2026 renewal. The functioning board homepage links the current regulation.
The qualification timeline is driven by the chosen route:
- Apprenticeship-certificate route: complete the approved program, receive the certificate, then document at least two years under a master licensee.
- No-certificate route: document at least seven years under a master licensee, obtain board approval, pass the bypass exam, then complete the Master-exam process.
- Reciprocity route: obtain required verification for individual licenses, subject to the plumbing-business-license exception, plus any experience or regulatory documents required for the licensing jurisdiction.
The online filing clock is separate: DPR says an unfinished DELPROS application must be submitted within six months after it is started. Do not open the application months before third-party records are ready. Use the contractor-license cost guide to budget document, exam, training and business costs beyond the application fee.
Reciprocity and substantially similar licenses
Reciprocity is a current-license review, not an automatic regional transfer. Delaware’s current table says Connecticut, Iowa and Maryland Master Plumber standards are substantially similar, so those applicants do not need to submit proof of experience for that comparison. Review the table on DPR’s Master Plumber page.
The same table identifies Alabama, Arkansas, the District of Columbia, Florida, Georgia, Michigan, New Hampshire, New Jersey, North Carolina, Ohio, Rhode Island, South Carolina, Virginia and West Virginia as not substantially similar. Applicants with a current Master Plumber license from those jurisdictions must prove at least seven years of practice after receiving master licensure there. An unlisted state or U.S. territory is evaluated by the board and requires a copy of that jurisdiction’s law and regulations.
Applicants generally must arrange direct license verification from each jurisdiction where they currently hold or have ever held a license; DPR says verification is not necessary for a plumbing-business license that covered all employees instead of the applicant individually. Read the exception in the Master Plumber instructions. Map individual licenses, including expired ones, before submitting so third-party verifications do not surprise the review.
Delaware plumbing license FAQ
What is Delaware’s state plumbing license? The board issues Master Plumber as the state plumbing license, but not every field worker must personally hold it. Delaware law allows specified apprentices, journeymen, mechanics, and others to work under qualifying master-plumber supervision, and other statutory exemptions may apply.
What is the journeyman certificate in the application? It is a completion certificate from a federally approved plumbing apprenticeship program. It qualifies an applicant for the route requiring at least two later years under a master licensee.
What if I do not have that certificate? Document at least seven years under a master licensee. If the board approves the experience, pass the Apprenticeship By-Pass Exam with at least 70%, then move through Master-exam approval.
How much is the Delaware plumber application fee? DPR currently lists $173 and says processing fees are non-refundable. Check the live fee schedule before paying.
Does Delaware have plumbing-license reciprocity? Delaware compares the current out-of-state Master Plumber license with its standards. The documentation depends on whether the jurisdiction is substantially similar, not substantially similar, or unlisted.
Can a Delaware Master Plumber perform all HVACR work? No. DPR says covered heating, air-conditioning, refrigeration, ventilation and process systems require the applicable Master HVACR or Master HVACR Restricted license in addition.
How often does a Delaware Master Plumber license renew? Biennially. Renewal requires the form, fee, and proof that the licensee met any board-established continuing-education requirements. The board says updated requirements take effect for the 2026 renewal.