Delaware Plumbing License: Master Plumber Requirements, Exam, Fees and Reciprocity (2026)

If you are searching for how to get a journeyman plumber license in Delaware, stop. There isn't one.

At a glance

• Who issues it: Board of Plumbing, HVACR Examiners (DPR)
• The only license: The Master Plumber license, the only permanent state plumbing license for individuals
• Routes: Journeyman certificate plus 2 years under a master, 7 years under a master, or reciprocity from a listed state
• Exam: Open book, 100 questions in 3 hours, $100 exam fee paid to ProV; score at least 70% to pass
• Fee: $173 application fee

Delaware issues exactly one permanent plumbing license to individuals, and it is the Master Plumber license (the only other plumbing credential the Board issues is a short term temporary license for a company that loses its license holder, covered below). There is no state journeyman plumber license, no state apprentice plumber license, and no tiered ladder of state licenses the way neighboring Maryland runs it with apprentice, journey and master levels. You are either a licensed master plumber in Delaware, or you are working under the supervision of one, or you are breaking the law.

That single structural fact changes almost everything about how a plumbing career and a plumbing business work in this state, and it is a fact that page one search results still get wrong. Several widely circulated guides describe a "Delaware journeyman plumber exam" and even quote an application fee for it. The Board itself says it "issues master plumber, master HVACR and master restricted HVACR licenses," and nothing else.

Here is what Delaware actually requires, checked against the Board's own pages, the statute, the Board's regulations, the exam vendor's bulletin and the state plumbing code, as of September 25, 2026. For the wider picture, see the Delaware contractor license guide or the national contractor license pillar.

Delaware plumbing license at a glance

Who regulates plumbing in Delaware

The Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, inside the Delaware Division of Professional Regulation (DPR), licenses plumbers. Its statutory authority is 24 Del. C. Chapter 18, and its rules sit at Title 24, section 1800 of the Delaware Administrative Code.

One board covers both trades. Under § 1803(b) its nine members are three master plumbers, three master HVACR or master HVACR restricted licensees and three public members, one of each from every county. The two license statutes are written as mirror images of each other.

The Board meets the second Tuesday of each month at 8:30 a.m., except June and December, in the Cannon Building in Dover, and reviews a complete application at its next scheduled meeting. A file completed the day after a meeting waits roughly a month. The Board office phone is (302) 744-4500.

Everything is filed through DELPROS, the Delaware Professional Regulation Online Services portal. There is no paper application path for the license itself, though several supporting documents still have to arrive at the Board office by mail from a third party. You have six months from the day you start a DELPROS application to submit it, or you restart from scratch.

What a Delaware Master Plumber is allowed to do

Under § 1807(a), you cannot provide plumbing services in Delaware, or hold yourself out as a "licensed plumber," "master plumber," or "licensed master plumber," unless you hold the license or fall inside a statutory exemption. Under § 1807(b), an expired, suspended or revoked license gives you no right to work at all.

The statute defines the scope in § 1802(15): the design, installation, construction, replacement, service, repair, alteration, or modification of the pipes, fixtures and other apparatus used for bringing the water supply into a building and removing liquid and water carried wastes from a building. Plumbing services also include the installation and connection of gas piping.

Note what is not in that scope. If you are working on heating, air conditioning, refrigeration, ventilation, or process cooling or heating systems, including the gas piping serving that equipment, the Board says you need a Master HVACR or Master HVACR Restricted license in addition to your Master Plumber license. A plumbing license does not cover mechanical work in Delaware, and a mechanical license does not cover water supply and waste. Contractors who do both routinely carry both.

Plumbing and HVACR: which Delaware license covers which work

Because the same Board licenses both trades, searches for "HVAC license Delaware" often land on plumbing pages. Here is how the statute splits the work.

Both master licenses carry the same $173 application fee on the Board's schedule. For the mechanical side in full, read our HVAC license Delaware guide.

The five exemptions: who can work without a license

§ 1807(c) lists the only ways to legally do plumbing work in Delaware without holding the license yourself:

1. Supervised workers. An apprentice, journeyman, mechanic, or other person providing plumbing services under the supervision of a master plumber who is that individual's employer, or who is employed full time by the same business entity as that individual.
2. Homeowners. An individual doing plumbing work other than gas piping in or about their own home, provided the home is not for sale and no part of it is offered to tenants, and provided they have filed a permit application with the authorized inspection authority.
3. Agricultural property. Work on property used exclusively for agricultural purposes, again with a permit application filed.
4. Local regulation. Work performed under § 1832.
5. HVACR work. Services authorized under Subchapter III, the HVACR subchapter.

Read the first exemption again, because it decides how a Delaware plumbing company has to be staffed. Delaware does not simply say your crew must be "supervised by a master." It specifies the employment relationship: the master must be their employer, or a full time employee of the same business entity.

Two more definitions tighten it. § 1802(18) defines "supervision" as control and oversight by a master licensee who is an owner or full time employee of the entity providing services, and makes that master responsible and accountable for the work. The Board's Regulation 1.2 defines a "Full Time Employee" as someone working a minimum of 30 hours per week, averaged over a period of 1 year, who is regularly paid by the entity and receives a W-2 form annually from it.

That is a statutory staffing requirement, not a paperwork formality, and we break down what it means for a plumbing business in Delaware's Full Time Employee Rule.

Penalties for unlicensed plumbing work

§ 1807(d) sets the fines directly in statute:

• First offense, not less than $1,500 and not more than $3,000
• Second or subsequent offense, not less than $3,000 and not more than $6,000

Justice of the Peace Courts have jurisdiction. These are floors as well as ceilings. The statute says "not less than," so a first offense cannot be settled for a token amount.

Separately, under § 1813(b), if the Board determines someone is providing plumbing services or using the title "master plumber" or "licensed plumber" contrary to the chapter, the Board shall request that the Attorney General's Office issue a cease and desist order, prosecute, or both. That is not discretionary language.

The routes to a Master Plumber license

§ 1808(a)(1) gives you exactly two paths by examination, and § 1810 adds reciprocity for masters licensed elsewhere.

Route 1, the apprenticeship route (2 years after your certificate). You hold a journeyman's certificate issued in any state following completion of a plumbing apprenticeship program that meets or exceeds the Federal Bureau of Apprenticeship and Training Standards, and after receiving it you performed plumbing services for 2 years under the supervision of a master plumber or someone holding a similar level of licensure in another state. You upload your apprenticeship Certificate of Completion.

The Board's application page is specific about what this "Journeyman Certificate" is: one issued by a federally approved plumbing apprenticeship program, such as the Delaware Department of Labor's. It is a training completion document. It is not a Delaware license, it does not let you work unsupervised, and it is the source of nearly all the confusion in this state.

Route 2, the experience route (7 years, plus a bypass exam). You performed plumbing services for 7 years under the supervision of a master plumber or equivalent out of state licensee, and then successfully completed the apprenticeship equivalency test approved by the Board and administered by a Delaware vocational technical school.

The Board reviews your experience first. If it approves, you are notified you may take the Apprenticeship By-Pass Exam, and you call one of three schools directly to schedule:

• New Castle County, New Castle County VoTech, (302) 683-3643
• Kent County, PolyTech High School, (302) 697-4545
• Sussex County, Sussex Tech, Georgetown, (302) 856-9035

You must pass the bypass exam with at least 70%. Five extra years of documented field time replaces the formal apprenticeship, but you sit an additional exam that Route 1 candidates never take.

Reciprocity: which states transfer to Delaware

Under § 1810(a), the Board licenses an applicant in good standing from a state, the District of Columbia or a territory whose standards are substantially similar to Delaware's. Under § 1810(b), an applicant from a jurisdiction that is not substantially similar must have practiced for a minimum of 7 years after licensure. The Board publishes the list:

Reciprocity applicants still send license verifications from every jurisdiction. The Board flags Pennsylvania specifically: plumbing licenses there are not issued by a state board, so if your only current license came from a Pennsylvania municipality, you must apply by examination. And a license from another state never lets you work here on its own; the Board's FAQ says you need a Delaware license to do any plumbing work in Delaware.

Proving your experience

Experience is proven by the Board's Verification of Employment form, completed by your supervisor. Under § 1808(c), all evidence of experience must be submitted by affidavit on Board approved forms, and the Board's application page adds that forms needing a supervisor signature, seal or notary may have to be mailed to the Board office.

The Board gives you fallbacks when a supervisor will not or cannot sign:

• If you cannot get the Verification of Employment form from the supervisor, you may substitute a W-2 or an affidavit of the employer or an officer of the employing company, but you must also enclose a written statement explaining why you cannot obtain the form.
• For periods of self employment, you may submit Schedule C.

Acceptance of proof of experience is explicitly at the Board's discretion. Build the strongest file you can rather than assuming a minimum will clear.

You also submit State/Jurisdiction Licensure Verification sent directly to the Board office from each state or jurisdiction where you currently hold or have ever held a license, and "jurisdiction" here includes cities and counties, not just states.

What the application may not ask you

§ 1808(c) contains an applicant protection that is worth knowing about, because it tells you what to push back on. The application form may not require you to submit:

• a photograph of yourself
• information related to citizenship
• place of birth
• length of state residency
• personal references

If a form or a third party service asks you for those things in connection with a Delaware plumbing license application, that requirement is not coming from the Board.

The exams: two vendors, in sequence

Delaware runs a two vendor system, and the order matters.

ABC Delaware. Associated Builders and Contractors Delaware administers the Apprenticeship By-Pass Examination when the Board requires it (the Route 2 path above; for plumbing the Board's licensure page directs candidates to the county vo-tech schools listed earlier). After you test, the vendor sends results to the Board. Once passing results are received and verified, Board staff forward your registration to the licensure exam vendor.

ProV Exam (Prov). ProV administers all required licensure examinations for the Plumbing and HVACR trades. Once the Board forwards your registration, ProV contacts you from a ProV email address within roughly 1 to 2 weeks with a Candidate Information Bulletin. Check your spam folder; the Board warns candidates about this directly.

ProV offers two formats:

• In person at four Delaware locations across Wilmington, Newark and Dover, by appointment, typically 2 to 5 days per week at 8:30 a.m., 9:00 a.m., 12:00 p.m. and/or 1:00 p.m. depending on the facility.
• Online via the Examroom service, by appointment, Monday through Friday, 8:00 a.m. to 4:30 p.m., on a compatible computer.

§ 1809(a) requires the written standardized exam to be offered at least quarterly, so there is a statutory floor on availability.

What is on the Master Plumber exam

ProV's published Delaware Candidate Information Bulletin (dated March 9, 2022) describes the Master Plumber exam as open book, 100 questions in 3 hours, with a $100 exam fee paid to ProV:

That bulletin permits the 2018 International Plumbing Code, the 2018 International Fuel Gas Code and Plumbing Basics for Contractors, 3rd edition. The bulletin ProV emails you after Board approval governs your sitting, so check its reference list before you buy books.

The passing score, and the three strikes rule

You must score at least 70% to pass.

Then there is a rule that can cost you a year. Under Board Regulations 2.2.2 and 3.1.6, you may retake a failed exam two more times without new Board approval, but applicants who do not pass after three attempts must reapply as a new applicant, obtain the Board's approval to sit again, and may not reapply until one full year has passed from the date they last took the examination. A Board order published in the April 1, 2026 Delaware Register of Regulations (29 DE Reg. 878), effective 10 days after publication and in force since April 2026, added one more sentence to Regulation 2.2.2: an applicant who fails an exam 3 times must wait at least 1 year from the date of the third failure to reapply for any type of plumbing license. Switching license categories does not shorten the wait.

Three failures does not mean "try again next month." It means a twelve month lockout plus a fresh application, fresh Board review, and a fresh fee. Plan your attempts accordingly.

After you pass, allow up to two weeks for the Board office to receive your official score. Once the Board has the score and confirms you have met all licensure requirements, the license is issued and you receive an email with your renewal and continuing education details.

How to get a Delaware plumbing license, step by step

1. Pick your route. Journeyman certificate plus 2 years under a master, 7 years under a master, or reciprocity from a listed state.
2. Line up your documents before you open the application. Verification of Employment forms from each supervisor (or the W-2, affidavit and explanation substitutes), Schedule C for self employment, and your apprenticeship Certificate of Completion if you have one.
3. Order license verifications from every state, city or county where you hold or have held a license, sent straight to the Board office.
4. Create a DELPROS account and start the Plumber application. Pay the $173 application fee by card. You have six months from the start to submit.
5. Wait for Board review at the next monthly meeting after your file is complete.
6. Route 2 only: pass the Apprenticeship By-Pass Exam with at least 70%.
7. Watch for ProV's email within 1 to 2 weeks of Board approval, then schedule the Master Plumber exam in person or online.
8. Pass with 70% or better and allow up to two weeks for the Board to receive your score.
9. Receive your license by email, then letter your work vehicles with "Licensed Plumber" and your license number in letters at least 3 inches high, as § 1806(a)(12) requires.
10. Set up the business layer before you sign a contract: the Division of Revenue contractor license, the Department of Labor notice, workers' compensation, and any county license where you will pull permits.

Delaware plumbing license fees

These are the Board's published fees as they appeared on its fee schedule when we read it on September 25, 2026. All fees are processed in DELPROS by credit or debit card. The Division does not accept cash, checks, or money orders by mail, and all processing fees are non-refundable.

Note the license type on the fee schedule is listed simply as "Plumber" at $173. If a guide quotes you a lower figure such as $141, it is out of date: an archived copy of the Board's own fee page from June 2021 shows the Plumber fee at $153, and the live page shows $173. § 1811 requires the Division to recompute fees at the beginning of each licensure biennium, so Delaware fees move on a two year cycle and stale numbers circulate constantly.

Renewal fees are not published in advance. You are notified of the amount at the time of renewal. If you renew after expiration you pay a late fee equal to 50% of the renewal fee on top of the renewal fee itself.

Renewal, continuing education and inactive status

§ 1812(b) makes the license renewable biennially, on payment of the fee, submission of the renewal form, and proof of any continuing education the Board requires. Every Delaware plumbing and HVACR license expires on October 31 of even numbered years, and DPR sends the renewal notice by email only.

The first CE deadline is October 31, 2026

Continuing education is new for this Board. Regulation 5.1 requires CE of all licensees, completed by October 31 of even numbered years starting in 2026. Regulation 5.3 sets the content:

Your first renewal is prorated based on when in the licensure period your license was issued, per the Board's published schedule:

• Licensed on or after 11/1 of even years but before 11/1 of odd years, 3 hours
• Licensed on or after 11/1 of odd years but before 7/1 of even years, 0 hours
• Licensed on or after 7/1 of even years to 11/1 of even years, 5 hours

Regulation 5.3.5 states the first renewal exceptions in different terms: a person licensed less than 1 year owes no CE at the first renewal, and a person licensed 1 year but less than 2 years owes 3 hours. The regulation is the binding text, so if the two seem to differ for your license date, confirm your number with the Board before the deadline.

For all subsequent renewals you owe 5 hours, unless you hold dual licenses, in which case Section 5 of the Board's Rules and Regulations governs. Courses must be Board approved and extra hours do not carry over. CE is tracked in DELPROS through the Continuing Education tab.

An important procedural detail: do not upload CE certificates into DELPROS unless you have been notified that you were selected for audit. You attest when you renew. From the 2026 renewals, the Board randomly audits 5% of renewals and 100% of late renewals. Only if selected do you enter course information and upload a certificate signed by the course presenter or a designated official of the sponsoring organization for each course.

Late renewal and inactive status

§ 1812(c) lets the Board set a late renewal window, capped by statute at no more than one year past the designated renewal date. The Board is blunt that this is not a grace period: practicing on an expired license is illegal even while you can still file late, and after the full year the license terminates.

§ 1812(d) allows a licensee to request inactive status for no more than five years, with reactivation requiring an application, the reactivation fee, and proof of CE. You must request it before your late renewal period ends (October 31 of odd years).

Discipline: what puts your license at risk

§ 1814 lists the grounds. Two are worth calling out for anyone thinking about how a company is staffed:

• § 1814(a)(1), fraud or material deception to acquire a license, allowing another person to use your license, or aiding or abetting an unlicensed person to represent themselves as licensed.
• § 1814(a)(6), violating any provision of the chapter or any lawful regulation under it.

Sanctions under § 1815 run from a letter of reprimand through censure, probation, suspension, revocation, and an administrative penalty not to exceed $500 for each violation. Under § 1816(b) and § 1804(c), the Board needs the affirmative votes of five or more members to find a violation and impose a sanction, and a licensee who disagrees may appeal to Superior Court within 30 days under § 1816(c).

Permits, inspections and the state plumbing code

The Division of Public Health adopted the 2021 International Plumbing Code, with Delaware amendments, as the "2021 State of Delaware Plumbing Code" (16 Del. Admin. Code 4455), and every county, city and town must enforce it as adopted or modified. The amendments a working plumber meets first:

• Who can pull a permit. DPH issues plumbing permits to Delaware licensed plumbers, or to homeowners whose homes are owner occupied and not for sale; the code limits homeowner work to a single family home the owner occupies, or will occupy, for not less than 1 year.
• Permit cost and life. DPH charges $100 per plumbing permit, and $100 per unit for apartments and condominiums. A DPH permit is valid for 1 year and fees are not refunded. Local jurisdictions set their own fees.
• Inspections. Each permit includes 3 inspections, counting failed, incomplete and inaccessible calls; each one after that costs $50. DPH has 3 working days to respond to a request.
• Responsibility. The code makes the master plumber "responsible for all work performed under a plumbing permit," and defines supervision of work as work under the master's permit while employed by the master or the same firm or owners.

DPH's own program permits and inspects statewide except where there are local jurisdictions, and its permit offices sit in Kent and Sussex Counties.

New Castle County and Wilmington

§ 1832 preserves local authority: nothing in Chapter 18 limits any county, municipality or other governmental entity from adopting and enforcing plumbing, HVACR or fuel gas codes and regulations that do not conflict with the chapter.

New Castle County requires a permit endorsed contractor license from its Department of Land Use for work that needs a county permit. Its 2026 requirements for the Master Plumber category list a $10,000 statutory compliance bond, liability insurance of at least $250,000 per occurrence and $500,000 aggregate, a copy of the license holder's current DPR license, a current Division of Revenue business license, and a total 2026 fee of $410 ($400 license fee plus a $10 ICC digital code access fee). If the license holder is not a principal of the company, the county requires a separate License Holder Acknowledgement form.

The City of Wilmington treats plumbing contractor licenses as tested licenses: its business license application tells plumbing and mechanical contractors to see the Chief Plumbing Inspector in the Department of Licenses and Inspections and pass the Trade Test before the city issues a business license.

The business layer: your Master Plumber license is not a contractor license

Your DPR Master Plumber license is a personal, individual credential. It says you are competent. It does not authorize a business to contract in Delaware. For that, you need a contractor business license from the Delaware Division of Revenue, under 30 Del. C. Chapter 25, an entirely separate agency and statute.

Under § 2502(a), any person wanting to do business in Delaware as a contractor obtains a license from the Division of Revenue for a fee of $75. It runs until January 1 and is renewed annually on or before December 31.

Timing is written into the statute. The license must be obtained, and proof of compliance made, prior to or in conjunction with the execution of a contract. On competitively bid contracts over $50,000, you must have initiated the license application before or with your bid, and if you are a subcontractor, before the general contractor submits its bid.

Under § 2502(b), the Division of Revenue will not issue the license until you have also:

• complied with the applicable provisions of § 375 of Title 30,
• filed a certificate of notice from the Delaware Department of Labor confirming you have notified them you are entering into construction contracts in Delaware, and
• filed a certificate of insurance showing workers' compensation coverage as required by Delaware law, or a Department of Labor form declaring you a qualified self insurer.

Gross receipts tax

Delaware's gross receipts tax is levied on the seller of goods or services rather than on the consumer, and contractors pay it on construction receipts. The Division of Revenue publishes the contractor rate at 0.6537% (.006537) of taxable gross receipts, with the first $100,000 per month exempt ($300,000 quarterly).

Monthly filers pay by the 20th of the following month; quarterly filers by the last day of the first month after the quarter closes. New licensees file quarterly through their first calendar year, after which the Division performs a "lookback" and may change your frequency.

The Division's worked example: $180,000 of receipts, less $15,000 paid to subcontractors, less the $100,000 exclusion, leaves $65,000 taxable and about $425 due.

Two gross receipts details that catch people:

• You may deduct amounts paid to subcontractors, but only if the subcontractor is licensed and subject to the chapter, a written agreement states the exact sums payable, and you attach Form 1280 listing each subcontractor's name, address, taxpayer ID, license number, business code and amount paid.
• You may not deduct architects, engineers, hauling, delivery, trash removal, utilities, operating expenses, or taxes and fees paid to any state, county, city or municipality; the Division's published list runs to 25 items.

Note also that § 2502(c)(1) as codified states the additional license fee at 0.6472%, while the Division of Revenue's published contractor guidance uses 0.6537%. Use the Division's published rate for filing and confirm the current figure with Revenue before you compute a return. An enterprise with common ownership or control gets only one exclusion, however many branches it runs.

If you are not a Delaware based business

All nonresident contractors must supply a surety or cash bond to the Division of Revenue equal to six percent (6%) of the total of all contracts exceeding $20,000 for construction in the state. Cash bonds and bank letters of credit from financial institutions are accepted.

Whoever hires you carries a duty too. Under § 2503, every architect, professional engineer, contractor or construction manager must notify the Department of Finance within 10 days of entering a contract with a nonresident contractor or subcontractor, reporting the total contract value and the names and addresses of the parties, on Form 5060. Failure to comply draws a civil penalty of up to $10,000 per occurrence, and willful or knowing failure is a misdemeanor punishable by a fine up to $3,000, imprisonment up to six months, or both.

Gross receipts rates, bonds, thresholds and penalties are set by statute and by the Division of Revenue and change. Check current figures with the Division before filing.

The sentence the Division of Revenue prints itself

The Division of Revenue's own contractor guidance carries the cleanest statement of Delaware's two layer system:

"The Business License Issued by the Division of Revenue is not a regulatory license and the issuance of such license does not attest to the qualifications of the applicant to perform the activity described on such license."

Your $75 business license proves you registered and you are paying gross receipts tax. It proves nothing about competence. The competence layer lives with the Board of Plumbing, HVAC and Refrigeration Examiners, and it attaches to a person, not to the company. For the general framing of that split, see State vs. Local Contractor License.

What this means if you want to run a plumbing company in Delaware

1. Delaware licenses only masters. There is no journeyman tier to fall back on.
2. Your crew's legal right to work depends on a master who is their employer or a full time employee of the same business entity (§ 1807(c)(1)), working at least 30 hours a week averaged over a year on a W-2 (Reg. 1.2).
3. If your company loses its sole license holder, § 1831 starts a hard clock:

The qualifier angle

A Delaware plumbing company without a master plumber in house is not a company with a staffing gap. Under § 1831 it has at most 100 days, and only if an owner or employee applies in time and receives the temporary license, before it must cease and desist. Many owners solve this by holding the license themselves. Owners who cannot, because they came from the business side, or because the license holder retired or left, need a licensed master who joins the business as a full time W-2 employee and actually supervises the work, because that is the only relationship the statute and the Board's regulation contemplate.

That is the whole reason qualifying agents exist, and Delaware's statute spells out the requirement in so many words.

Our founders, Marshall Schofield and Jeremiah Jaskulski, built The Licensing Company around this model: a licensed master who becomes a real employee of the company, on payroll, overseeing the plumbing work, which is how a qualifying agent qualifies a Delaware company under § 1807(c)(1).

If you are on the licensing side of that equation, start with What Is a Qualifying Agent? If you need one placed in your business, Hire a Qualifying Agent walks through how the W-2 placement works. If you are a licensed master weighing whether to serve as one, see Become a Qualifying Agent.

Frequently asked questions

Does Delaware have a journeyman plumber license? No. The Division of Professional Regulation issues a Master Plumber license to individuals and nothing below it. What people call a "journeyman certificate" in Delaware is a completion certificate from a federally approved apprenticeship program, such as the Delaware Department of Labor's. It shortens your path to the master license from seven years to two, but it is not a state license and it does not let you work on your own.

How do I become a plumbing apprentice in Delaware? Get hired by a registered apprenticeship sponsor first; the Department of Labor says you apply to the employer, not the Department. The minimum age is 16, and the apprenticeship regulation (19 Del. Admin. Code 1101) recommends at least 144 hours of related instruction for each year of the apprenticeship. School tuition is waived only for registered apprentices.

How long does it take to become a licensed Master Plumber in Delaware? Two years of supervised work after a federally approved apprenticeship certificate, or seven years of supervised work plus the Apprenticeship By-Pass Exam. Add Board review time, the exam scheduling window (ProV contacts you 1 to 2 weeks after the Board forwards your registration), and up to two weeks for the Board to receive your official score.

What does a Delaware plumbing license cost? The Board's application fee is $173, plus the ProV exam fee ($100 per attempt in its published bulletin). The Division of Revenue contractor license is $75 a year, plus gross receipts tax above the monthly exclusion and the 6% nonresident bond if you are based outside Delaware. Fees change each biennium, so check before budgeting.

Does Delaware accept my plumbing license from another state? Possibly, under § 1810. A current master license from Connecticut, Iowa or Maryland needs no proof of experience; the fourteen jurisdictions the Board lists as not substantially similar need seven years of practice after licensure; any other state is evaluated case by case. A Pennsylvania municipal license does not qualify.

When is the first continuing education deadline? October 31, 2026. A plumbing licensee owes 5 hours (3 in code changes, 1 in safety, 1 in cross connections and backflow), subject to the first renewal proration, and a dual plumbing and HVACR licensee owes 6.

Can I use a master plumber who works for another company as my qualifier? No. § 1807(c)(1) exempts supervised workers only where the supervising master is their employer or is employed full time by the same business entity, and Regulation 1.2 sets full time at 30 hours a week averaged over a year, paid on a W-2. § 1814(a)(1) also makes allowing another person to use your license grounds for discipline.

What happens if my company's only licensed plumber quits? § 1831 governs. Notify the Board in writing within 7 days, and the Board holds an emergency meeting within 10 days, where an owner or employee who has already applied may receive a 100 day temporary license. The temporary holder must sit the next available exam, and when the 100 days run out with no license holder employed, the company must cease and desist.

Do I need both a plumbing and an HVACR license? Possibly. A Master Plumber needs a Master HVACR or Master HVACR Restricted license as well for heating, air conditioning, refrigeration, ventilation or process equipment, including the gas piping serving it, and a Master HVACR needs a Master Plumber license for water supply and waste. See HVAC License Delaware for the mechanical side.

Can a homeowner do their own plumbing in Delaware? Yes, within limits. § 1807(c)(2) covers plumbing other than gas piping in your own home if it is not for sale and a permit application is filed, and the state plumbing code limits it to a single family home you occupy for at least a year.

Can I be licensed in Delaware if I have a criminal record? Possibly. Under § 1808(a)(5), the Board, or between meetings the Board President or designee, shall waive a substantially related conviction if, after the factors in 29 Del. C. § 8735(x)(3), a waiver does not create an unreasonable risk to public safety. § 1808(a)(6) carves out felony sexual offenses, and Board Regulation 8.0 lists the crimes treated as substantially related; take your facts to the Board or to counsel.

Talk to us about staffing a Delaware plumbing company

If you are opening a plumbing company in Delaware, expanding into the state from Maryland or Pennsylvania, or facing the § 1831 clock after losing your license holder, call 615-219-2110. We will walk through what the Board, the county and the Division of Revenue need from your company, and whether a full time qualifying agent placement fits. You can also start online at Hire a Qualifying Agent or review Consultation Packages.

Related Delaware guides: HVAC License Delaware · Electrician License Delaware · Delaware's Full Time Employee Rule · Delaware Contractor License Guide · Contractor License Requirements · All State Guides

Sources

All retrieved 2026-09-25. Fees, rates and requirements are set by the Board, the Division of Public Health, the Division of Revenue, the counties and the General Assembly and are subject to change; confirm with the agency before relying on any figure.

• Delaware DPR, Board of Plumbing, HVACR Examiners home page (retrieved 2026-09-25)
• Delaware DPR, Master Plumber Licensure (retrieved 2026-09-25)
• Delaware DPR, Examinations (retrieved 2026-09-25)
• Delaware DPR, Fee Schedule (retrieved 2026-09-25)
• Delaware DPR, License Renewal (retrieved 2026-09-25)
• Delaware DPR, Continuing Education and Audit Information (retrieved 2026-09-25)
• Delaware DPR, Temporary Plumber or HVACR (retrieved 2026-09-25)
• Delaware DPR, Plumbing and HVACR FAQs (retrieved 2026-09-25)
• Delaware DPR, Master HVACR and Master HVACR Restricted Licensure (retrieved 2026-09-25)
• Delaware DPR, Fee Schedule, archived copy of June 5, 2021 (retrieved 2026-09-25)
• 24 Del. C. Chapter 18, Subchapter I (§§ 1801 to 1806) (retrieved 2026-09-25)
• 24 Del. C. Chapter 18, Subchapter II (§§ 1807 to 1817) (retrieved 2026-09-25)
• 24 Del. C. Chapter 18, Subchapter IV (§§ 1831 and 1832) (retrieved 2026-09-25)
• 24 Del. Admin. Code 1800-1.0, General Provisions (retrieved 2026-09-25)
• 24 Del. Admin. Code 1800-2.0, Plumbing Licensing Requirements (retrieved 2026-09-25; this copy predates the April 2026 amendment below)
• Delaware Register of Regulations, Final Order amending 24 Del. Admin. Code 1800 subsections 2.2.2 and 3.1.6, 29 DE Reg. 878 (April 1, 2026), with the full current regulation (retrieved 2026-09-25)
• 24 Del. Admin. Code 1800-5.0, Continuing Education and Renewal Audits (retrieved 2026-09-25)
• 24 Del. Admin. Code 1800-8.0, Crimes substantially related to plumbing services (retrieved 2026-09-25)
• ProV, Delaware Division of Professional Regulation Candidate Information Bulletin (dated March 9, 2022) (retrieved 2026-09-25)
• 16 Del. Admin. Code 4455-2.0, State of Delaware Plumbing Code amendments (retrieved 2026-09-25)
• Delaware Division of Public Health, Plumbing Program (retrieved 2026-09-25)
• 30 Del. C. Chapter 25, Contractors' License Requirements and Taxes (retrieved 2026-09-25)
• Delaware Division of Revenue, Tax Tips for Contractors and Real Estate Developers (retrieved 2026-09-25)
• Delaware Division of Revenue, Form 5060 (retrieved 2026-09-25)
• Delaware Division of Revenue, Gross Receipts Tax (retrieved 2026-09-25)
• Maryland Board of Plumbing, License Requirements (retrieved 2026-09-25)
• New Castle County Department of Land Use, 2026 Utility Contractor Requirements (retrieved 2026-09-25)
• New Castle County, Permit Endorsed Contractor License (retrieved 2026-09-25)
• City of Wilmington, Application for Business License (retrieved 2026-09-25)
• Delaware Department of Labor, Apprenticeship and Training FAQ (retrieved 2026-09-25)
• 19 Del. Admin. Code 1101, Apprenticeship and Training Regulations (retrieved 2026-09-25)