Delaware Plumber License Requirements (2026)

Delaware licenses Master Plumbers statewide through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners. State law permits an apprentice, journeyman, mechanic, or other worker to perform plumbing services only under the supervision of a master plumber who is the worker’s employer or a full-time employee of the same business. Delaware’s Board does not issue a separate state journeyperson plumber license; the “Journeyman Certificate” in the master-licensure pathway comes from a federally approved apprenticeship program. A Master Plumber who conducts business also needs the appropriate Delaware business license, and state licensure does not replace locally administered permits or inspections.

Regulatory Body

Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners (DPR) administers the credential or scope-specific rules discussed here under 24 Del. C. ch. 18; 24 DE Admin. Code 1800. Whether that pathway applies depends on the work scope and conditions explained below. The Board issues statewide Master Plumber, Master HVACR, and Master HVACR Restricted licenses.

• Official portal: https://dpr.delaware.gov/boards/plumbers/
• Address: Cannon Building, Suite 203, 861 Silver Lake Blvd., Dover, DE 19904
• Phone: (302) 744-4500

Eligibility Requirements

Applicants must be at least 18 years old. Check the current application for identification and tax-number requirements. State law prohibits the Board’s application from requiring citizenship, place of birth, length of Delaware residency, or personal references.

Good moral character

Applicants must meet the statutory conduct and fitness standards. The Board can consider substantially related convictions and may waive a conviction-based restriction after reviewing the statutory public-safety factors; a felony sexual-offense conviction is not subject to that time limitation.

Background investigation

The published master-plumber materials require licensing and disciplinary-history information. The statute does not describe a universal fingerprint-based background check for every applicant.

Experience and Education

The applicant must document and verify at least 2 years of Qualify either with a journeyman certificate issued after completing a federally approved plumbing apprenticeship program plus two years of work under a master plumber (or equivalent out-of-state licensee), or with seven years of supervised plumbing work plus the Board-approved Apprenticeship By-Pass examination.. Keep payroll, tax, project, or supervisor records to support the claim, as the board can request proof for any period within its lookback window.

Accepted proof of experience or eligibility

• Certificate of completion from the federally approved apprenticeship program, if using the journeyman-certificate route
• Verification of Employment forms from supervisor(s)
• W-2 forms or an employer/officer affidavit with an explanation if a supervisor form is unavailable
• Schedule C for self-employment periods, where applicable

Education substitution

The published statutory routes are the federally approved apprenticeship/journeyman-certificate route or the seven-year supervised-work route followed by the Board-approved Apprenticeship By-Pass examination. Do not assume a general trade-school substitution.

Exam Requirements

Testing provider or authority: ProV Exam, after Board approval; ABC Delaware administers the Apprenticeship By-Pass examination when required. The following examination requirements cover the pathways described in this guide; follow each part's classification, waiver, and local-scope conditions. Unpublished format details do not remove an examination requirement:

• Delaware Master Plumber written standardized examination — question count: confirm with the authority, timing: confirm with the authority, passing score: confirm in the current candidate bulletin
• Apprenticeship By-Pass examination, if required for the seven-year route — question count: confirm with the authority, timing: confirm with the authority, passing score 70%

Examination fee: DPR directs approved candidates to ProV for current master-examination fees. The current Board fee schedule does not list a standard Master Plumber examination fee.

Retake policy: State law permits a retake at the next available examination date. After three unsuccessful attempts, Board rules may prescribe conditions for a further retake. A DELPROS application must be submitted within six months after it is started.

Insurance and Bonds

This credential carries no state-level surety bond requirement under the cited sources. Individual jobs may still trigger a permit or public-works bond, which should be verified before bidding.

General liability

The Board’s current Master Plumber licensure materials do not state a statewide general-liability minimum. Confirm insurance obligations imposed by the business-license, permit, contract, or local authority requirements.

Workers' compensation

Workers’ compensation obligations are separate from the Board’s individual Master Plumber license. Confirm current employer obligations with Delaware’s workers’ compensation authorities before hiring staff.

Additional financial requirements

The Board’s current Master Plumber application materials do not identify a bond or financial-statement requirement for the individual license.

Fee Schedule

To turn these board fees into a realistic year-one budget — bond premium, liability insurance, and exam prep included — open the cost calculator preloaded for Delaware plumber.

Renewal and Continuing Education

Expect to renew the Delaware Master Plumber License every 2 years. The cited materials name no distinct statewide fee for renewal. Licenses expire October 31 of even years. A late renewal may be filed for up to one year, but practice is illegal until the license is renewed; the late fee is 50% of the renewal fee.

Continuing education: For subsequent renewals, five hours of continuing education are required unless the licensee has dual licenses. First-renewal hours vary by the date the license was issued during the licensing period.

Reciprocity

Delaware does not accept the NASCLA Accredited Examination for this classification.

Delaware provides statutory reciprocity. Applicants with current, good-standing licenses from jurisdictions with substantially similar standards may qualify; applicants from jurisdictions that are not substantially similar must document at least seven years of practice after master licensure and meet the other statutory requirements.

Weighing more than one jurisdiction? The national hub compares published Plumber license requirements by state — exam, bond, fee, and experience thresholds side by side.

Plumber Licensing in Neighboring States

Contractors working near a state line, or weighing where to qualify first, should compare Delaware's requirements against the bordering jurisdictions before committing to an application:

• Maryland Plumber License Requirements — Maryland Master Plumber/Gas Fitter
• New Jersey Plumber License Requirements — New Jersey Master Plumber License
• Pennsylvania Plumber License Requirements — Pennsylvania Plumber — Local Licensing; No Statewide Trade License

Step-by-Step Application Roadmap

1. Select the correct examination eligibility route. Use the federally approved apprenticeship/journeyman-certificate route plus two years of supervised work, or the seven-year supervised-work route that requires the Apprenticeship By-Pass examination.
2. Collect third-party experience records. Arrange certificates, supervisor Verification of Employment forms, license verifications, and permitted substitute tax or affidavit records.
3. Complete the Apprenticeship By-Pass examination if required. For the seven-year route, Board approval is required before taking the By-Pass exam through a Delaware vocational-technical school; the posted passing score is at least 70%.
4. Apply through DELPROS for examination approval. Submit the application, fee, and required evidence. The Board reviews complete applications and sends approved candidates their ProV examination information.
5. Pass the Delaware Master Plumber examination. Take the Board-designated written standardized examination with ProV after Board approval.
6. Secure the Delaware business license when conducting business. The professional license is separate from the Delaware Division of Revenue business-license obligation.
7. Confirm local project approvals. Before beginning work, confirm locally administered permits, inspections, and applicable code requirements.
8. Renew and complete continuing education. Master Plumber licenses renew biennially. Subsequent renewals generally require five hours of continuing education, subject to the Board’s dual-license and first-renewal rules.

Application Checklist

The most critical documents or confirmations the applicant should have in hand before filing with DPR:

• Federally approved apprenticeship certificate plus two years of supervised work, or seven years of supervised work
• Supervisor Verification of Employment forms and permitted substitute evidence
• State/jurisdiction license verification from every jurisdiction ever licensed in
• Apprenticeship By-Pass exam pass at 70% or higher, if using the seven-year route
• DELPROS application and $173 nonrefundable processing fee
• Board approval and passing Master Plumber examination result from ProV
• Division of Revenue business-license review, if conducting business
• Local permit and inspection confirmation for each project

Progress is saved in this browser, so you can return to this checklist while your application is in flight.

Common Filing Mistakes

Based on the board's own instructions and the sources cited here, the problems below are what most often stall a Delaware Plumber application.

Assuming Delaware issues a state Journeyperson license

The Board issues Master Plumber licenses. The journeyman certificate used in the examination route comes from a federally approved apprenticeship program, not a separate Delaware Board credential.

Using the wrong eligibility route

The route with a federally approved apprenticeship/journeyman certificate requires two years of supervised work; the non-certificate route requires seven years and the Apprenticeship By-Pass exam.

Trying to schedule before Board approval

DPR requires the Board to approve the master-exam application before it sends the candidate information required for ProV scheduling.

Ignoring third-party verifications

DPR requires jurisdictional license verifications and experience evidence. Supervisor forms, permitted W-2/affidavit substitutes, and Schedule C records have specific use cases.

Missing local project approvals

The statewide Master Plumber license does not replace locally administered permit, inspection, or code requirements.

Letting CE slip

Subsequent renewals generally require five continuing-education hours, with special first-renewal and dual-license rules.

Study and Reference Materials

The references below are either cited by the board, used during the application, or standard preparation for the trade. They are listed purely for convenience — CLR earns no commission on any of them.

• Delaware Master Plumber licensure requirements — Delaware DPR. Use the current DPR route-specific evidence and DELPROS instructions.
• 24 Del. C. §§ 1807–1812 — Delaware Code Online. Statutory plumbing scope, qualifications, examination, reciprocity, and renewal framework.
• ProV Master Plumber exam information — ProV Exam. Confirm the current examination handbook, fees, references, and scheduling terms after Board approval.

Other Delaware Trade Licenses

If the Plumber license is not the right fit, the following published Delaware trade guides are also covered by CLR:

• Delaware General Contractor License Requirements
• Delaware Electrician License Requirements
• Delaware HVAC Technician License Requirements
• Delaware Roofing Contractor License Requirements
• Delaware Painting Contractor License Requirements
• Delaware Landscaping Contractor License Requirements
• Delaware Masonry Contractor License Requirements
• Delaware Concrete Contractor License Requirements
• Delaware Carpentry Contractor License Requirements
• Delaware Solar Installer License Requirements
• Delaware Low-Voltage Technician License Requirements
• Delaware Fire Sprinkler Contractor License Requirements
• Delaware Home Inspector License Requirements
• Delaware Pool Contractor License Requirements
• Delaware Handyman License Requirements
• Delaware Pest Control License Requirements
• Delaware Septic Contractor License Requirements

Frequently Asked Questions

What plumbing license does Delaware issue?

The Board issues the statewide Master Plumber license. Apprentices, journeymen, mechanics, and other workers may perform plumbing services under the statutory supervision exception; Delaware’s Board does not issue a separate state Journeyperson Plumber license.

How do I qualify for Delaware Master Plumber licensure by examination?

You need either a federally approved apprenticeship program’s journeyman certificate plus two years of supervised work, or seven years of supervised work plus the Board-approved Apprenticeship By-Pass examination. Both routes then require the Board-designated master examination.

Who administers the Delaware Master Plumber examination?

After Board approval, DPR uses ProV Exam for the required plumbing/HVACR licensure examinations. ABC Delaware administers the Apprenticeship By-Pass exam when the Board requires it.

Does Delaware have Master Plumber reciprocity?

Yes. Current, good-standing licenses from substantially similar jurisdictions can qualify. Where a jurisdiction is not substantially similar, the applicant must document at least seven years of practice after licensure and meet the other statutory conditions.

Do I need a business license in addition to the Master Plumber license?

Professional licensure and Delaware business licensing are separate. A person conducting business should verify the appropriate Division of Revenue business-license requirement in addition to Board licensure.

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