Delaware · Plumbing licensing · official-source guide
Delaware licenses the individual master plumber through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, with no journeyman license in the chapter. Every plumbing business also needs a Division of Revenue business license at $75 a year. Expect two years of supervised experience after a Journeyman Certificate, or seven without one, and a 70 percent exam.
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Verify a licenseVerified against agency sources on 2026-09-11. Rules and fees change; confirm with the named authority before relying on this guide.
Delaware licenses plumbers through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, one of the professional boards administered by the Division of Professional Regulation in the Department of State. The Board's authority sits in Title 24, Chapter 18 of the Delaware Code, and its rules sit in the Delaware Administrative Code at 24 DAC 1800. Everything transactional runs through DELPROS, the Division's online licensing system, from the first application to every renewal. The Board issues three credentials on this side of the house: Master Plumber, Master HVACR, and Master Restricted HVACR, which limits practice to a named specialty such as air conditioning. A temporary plumber or HVACR license also exists. The statute defines plumbing services broadly. Under 24 Del. C. 1802(15), plumbing services means 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, and it also includes the installation and connection of gas piping. Gas piping is inside the Delaware plumbing license, not beside it. There is a second license every plumbing business in Delaware needs and it comes from a completely different agency. The Division of Revenue issues the state business license, and any contractor conducting business activity in Delaware is required to register with and obtain one. Delaware regulates the person through the Board and the business through Revenue, and the two have nothing to do with each other.
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Delaware skips a rung that most states have. The Board's licensure pages list Master Plumber, Master HVACR and Master Restricted HVACR, and the code chapter carries no definition of a journeyperson plumber and no journeyperson plumbing license. Under 24 Del. C. 1802(13), master plumber, licensed plumber and licensed master plumber all mean the same thing: an individual holding a current license to provide plumbing services issued under this chapter. One license, one title. The requirement to hold it is in 24 Del. C. 1807, which provides that a person shall not provide plumbing services in this State nor hold oneself out to the public as being a licensed master plumber without proper licensure, with limited exceptions for apprentices, homeowners and agricultural work. Read the second half of that sentence. Holding yourself out to the public as a licensed master plumber is regulated separately from doing the work, so a website claim is exposure on its own. Unlicensed people can still work, but only under supervision. Section 1807(c)(1) allows unlicensed work under a licensed master plumber's supervision, and that supervision structure is what apprentices and helpers operate inside. A journeyman certificate does exist as an input to licensure rather than as a license: the Board's new license page treats an applicant holding a Journeyman Certificate differently from one who does not. Delaware also protects the licensed master plumber against a firm losing its only credentialed person. Section 1831 addresses what happens when a partnership, firm, corporation or other artificial entity that provides regulated services suffers the loss of its sole license holder.
Sourcesdpr.delaware.gov 1delcode.delaware.gov 2delcode.delaware.gov 3delcode.delaware.gov 4dpr.delaware.gov 5
The Board publishes two experience routes to the Delaware master plumber license and they are very different in length. The short route is for an applicant who already holds a Journeyman Certificate. That applicant needs at least two years of work experience under the supervision of a master licensee after receiving the Certificate. The long route is for an applicant without a Journeyman Certificate, who needs at least seven years of work experience under the supervision of a master licensee. Section 1808 of the code describes the same two paths: completion of an approved apprenticeship plus two years of supervised experience, or seven years of supervised experience plus an apprenticeship equivalency test. That equivalency test is called the Apprenticeship By-Pass Exam and requires a score of at least 70 percent. Documenting the experience is specific. Supervisors complete the Board's Verification of Employment form. Where that is impractical, the Board will accept a tax form W-2 or an affidavit of the employer. For applicants who were self employed, the Board accepts a Schedule C. Beyond experience, section 1808 also requires passing the standardized examination, no outstanding administrative penalties, no substance impairment, and no pending disciplinary proceedings or disqualifying convictions. The gap between two years and seven years is the whole argument for completing a registered apprenticeship first rather than accumulating informal field time. Five years is a long detour, and the Board's documentation standard means informal years have to be provable with employer records anyway.
The Division of Professional Regulation uses an outside testing vendor. The Board states that the Division utilizes the external testing vendor ProV Exam to facilitate all required licensure examinations for the plumbing and HVACR trade. The sequence matters because it is the opposite of many states. You apply first through DELPROS, the Board approves the application, and only then does ProV contact you by email, typically within one to two weeks, to schedule. You cannot book a seat before approval. Testing can be done in person at Delaware locations or online through Examroom. The passing score is stated plainly: you must obtain a minimum score of 70 percent to pass the exam. ProV sends a Candidate Information Bulletin that lists the permitted testing materials for use during the licensure examination and a breakdown of the testing criteria for each licensure examination, so the reference list and the content weighting come from that bulletin rather than from the Board's website. The Board's rules require the exam to be offered at least quarterly, and section 1809 of the code repeats that the written standardized examination must be offered at least quarterly. Retakes are limited. Plumbing and HVACR applicants who do not receive a passing score after three attempts must reapply as a new applicant, and may not reapply until one year has passed from the date they last took the examination. That one year lockout is the reason to treat the third attempt as the last one and prepare accordingly.
Sourcesdpr.delaware.gov 1delcode.delaware.gov 2archive.regulations.delaware.gov 3
Delaware's Board fee schedule is short. The application fee for a Plumber license is $173. Master HVACR is $173. Master Restricted HVACR is $173. A Plumber or HVACR Temporary license is $40. A Commercial Hood System Examination costs $50. The renewal fee is handled differently from most states and the Board says so: you are notified of the amount of the renewal fee at the time of renewal, so the figure is set per cycle rather than published as a standing number. What is published is the late penalty formula. When you submit a renewal application after the expiration date, you must pay a late fee in addition to the renewal fee, and the late fee is 50 percent of the renewal fee. That is a percentage rather than a flat charge, which means letting a license sit expired is priced against whatever the renewal happens to be that cycle. The ProV examination fee is billed by ProV and does not appear in the Board's fee schedule. Outside the Board, the Division of Revenue charges $75 for the contractor business license, renewable annually on or before December 31. Delaware's general business license runs for one year expiring December 31, or a business may take a three year renewal at triple the annual fee. Municipal fees are separate again. Wilmington charges $200.00 for a Plumbing Contractor business license under code 1007 and $25.00 for its annual city master plumber license.
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Delaware plumbing licenses are biennial, not annual. The Board states that plumbing and HVACR licenses expire on October 31 of even years. Section 1812 of the code puts it the same way: a license is renewable biennially in a manner determined by the Division, upon payment of the appropriate fee and proof of continuing education completion. Renewal runs through DELPROS. There is a grace window and a hard cliff behind it. A licensee may file a late renewal application for up to one year after the expiration date, paying the late fee in addition to the renewal fee. Past that, the language is unforgiving. If the license is not renewed within one year of expiration it will terminate, and to resume practicing in Delaware you must reapply in DELPROS as a new applicant. Reapplying as a new applicant means the full application, the fee, and potentially the examination again, so a lapse past thirteen months is far more expensive than it looks. Inactive status is the planned alternative. Section 1812 provides for inactive status for up to five years, which is the right tool for a licensee stepping away from the trade rather than letting the credential die quietly. For a business, the operational point is that the two year cycle makes the renewal easy to forget. There is no annual touchpoint to remind you. Put October of every even year on the calendar with the continuing education deadline four months earlier.
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Delaware's plumbing continuing education requirement is small and its timing is unusual. Board rule 5.3 provides that licensees shall complete 5 hours of approved continuing education during each renewal period. Rule 5.1 sets the deadline: continuing education is required of all licensees and shall be completed by June 30 of any year in which a license is to be renewed, starting October 31, 2024. So the hours are due four months before the license expires, not at renewal. The first renewal after initial licensure is prorated on a sliding scale published by the Board, and it depends on when in the biennium the license was issued. A licensee first licensed on or after November 1 of an even year but before November 1 of the following odd year owes 3 hours. A licensee first licensed on or after November 1 of an odd year but before July 1 of the following even year owes 0 hours. A licensee first licensed on or after July 1 of an even year up to October 31 of that even year owes 5 hours. Every renewal after the first is 5 hours, unless the licensee holds dual licenses. The Board approves the course list and publishes it, so a course that is not on the approved list does not count. Random audits are performed by the Board to ensure compliance with the license requirements, and proof of completion is what an audit asks for. Keep the certificates.
Sourcesdpr.delaware.gov 1archive.regulations.delaware.gov 2delcode.delaware.gov 3
Delaware has one of the more usable reciprocity pages in the country because it names the states and splits them into two tiers. Under 24 Del. C. 1810, licensed plumbers from other jurisdictions with substantially similar standards may be licensed here, and those from jurisdictions with different standards must have seven or more years of post licensure practice experience. The Board applies that in practice as follows. If you hold a current license in Connecticut, Iowa or Maryland, no experience documentation is required, because those three are treated as having substantially similar standards. If you hold a current license in Alabama, Arkansas, the District of Columbia, Florida, Georgia, Michigan, New Hampshire, New Jersey, North Carolina, Ohio, Rhode Island, South Carolina, Virginia or West Virginia, you must provide proof of practicing a minimum of seven years after receiving licensure as a Master. The Board's FAQ restates the general standard: if you hold a current license in another United States state, territory or the District of Columbia where the licensure requirements are substantially similar to Delaware's, you may be licensed by reciprocity. Board rule 2.3.1 puts the burden on the applicant, who must demonstrate that the standards for licensure of the state through which the applicant seeks reciprocity are equivalent to those of this State. The Board is also clear that out of state licensure is not a substitute for Delaware licensure. The Board must issue you a license to do any plumbing or HVACR work in Delaware, regardless of what you hold elsewhere.
Sourcesdpr.delaware.gov 1delcode.delaware.gov 2dpr.delaware.gov 3archive.regulations.delaware.gov 4
A Delaware master plumber license does not let a business invoice anyone. That comes from the Division of Revenue, and the Division states that any contractors conducting business activity in Delaware are required to register with and obtain a business license from it. The Division's own tax guidance for contractors carries the numbers. A contractor is required to obtain a business license at $75, which must be renewed annually on or before December 31. Every contractor must then pay gross receipts tax. The Division's contractor tax tip states the rate as .6537 percent, while 30 Del. C. 2502 states 0.6472 percent of the aggregate gross receipts paid to the contractor, so confirm the current rate with the Division before filing rather than relying on either figure alone. There is a substantial exclusion before the tax bites. The first $100,000 of construction gross receipts received per month is exempt, or $300,000 quarterly. Filing deadlines are the twentieth day of the following month for monthly filers and the last day of the first month after the end of the calendar quarter for quarterly filers. One more timing rule catches bidders. Under 30 Del. C. 2502, contracts exceeding $50,000 that are competitively bid require the license application to be initiated before the bid is submitted. Delaware's general business license runs one year and expires December 31, with a three year option at triple the annual fee, and applications go through the Delaware One Stop portal.
Sourcesrevenue.delaware.gov 1revenuefiles.delaware.gov 2delcode.delaware.gov 3firststeps.delaware.gov 4
Delaware treats non resident contractors differently and the requirement is a cash cost, not a form. The Division of Revenue states that all non resident contractors must supply a surety or cash bond to the Division of Revenue equal to six percent of the total of all contracts exceeding $20,000. That is six percent of the contract total, posted before the work, on every contract above the threshold. For a plumbing contractor crossing from Maryland, Pennsylvania or New Jersey to take a Delaware job, that is working capital tied up per contract rather than a single annual bond. There is a reporting duty that runs the other way as well, and it lands on the party hiring the non resident. Every architectural or professional engineering firm, contractor or construction company engaging in the practice of such profession must furnish the Department of Finance, within 10 days after entering into any contract with a contractor or subcontractor who is not a resident, notice of that contract. Missing that report is priced. Section 2503 of Title 30 provides a $10,000 civil penalty, or a misdemeanor fine up to $3,000 and up to six months imprisonment, for failing to report non resident contractor contracts. So a Delaware plumbing company that subcontracts to an out of state firm has its own filing obligation and its own exposure. Before signing an out of state subcontractor, confirm the bond is posted and file the notice inside ten days. The Division of Revenue takes bonding questions at 302-577-8167.
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Delaware has the most specific vehicle display rule of the three states covered here, and it is in the statute rather than in a regulation. Under 24 Del. C. 1806(a)(12), the Board shall require that all persons licensed in plumbing and HVACR services display the words Licensed Plumber and or Licensed HVACR and the license number assigned to them in not less than 3-inch letters and numbers on the vehicles used in the performance of their work. Break that into its four parts. The words Licensed Plumber, spelled out, not an abbreviation. The license number assigned to you. Both in letters and numbers of at least three inches. On the vehicles used in the performance of your work, which reaches the service van and the truck, not only the wrapped lead vehicle. Three inches is a large mark. A typical wrap designer will size a phone number larger than a license number, so this is the item most likely to be wrong on a fleet that otherwise looks professional. Check it with a tape measure rather than by eye. The same statutory subsection is the Board's authority, so compliance is a Board matter and sits alongside the Board's other disciplinary powers. Two things follow for a contractor. First, the phrase Licensed Plumber on the truck is itself protected language under 24 Del. C. 1807, so displaying it while unlicensed is a separate violation. Second, the number you are required to paint is the number that resolves in the state license lookup, which makes the truck a verification tool as well as an ad.
The prohibition is in 24 Del. C. 1807, which bars providing plumbing services in Delaware and bars holding oneself out to the public as a licensed master plumber, with limited exceptions for apprentices, homeowners and agricultural work. The money consequences sit in the Division of Professional Regulation's own enabling statute at 29 Del. C. 8735. Under subsection (s)(1) the Division may investigate unlicensed practice and issue a citation to the person engaging in it. Under subsection (s)(2) the penalty for the first occurrence of unlicensed practice by an individual, or unlicensed operation of a facility, shall be no more than $250. Under subsection (s)(4) any person or facility who either admits, or after a hearing is found guilty of, engaging in unlicensed practice may be fined up to $1,000 per day for every day such unlicensed practice occurs. Per day is the part to notice. A job that runs three weeks is priced as twenty one violations, not one. The same subsection provides that admitted violations may be referred to appropriate law enforcement agencies, including the Delaware Department of Justice, for criminal prosecution, so the civil citation is not necessarily the end of it. Separately, on the business side, operating without the Division of Revenue license and failing to report a non resident contractor contract carry their own penalties under Title 30. A contractor in Delaware has three distinct compliance surfaces: the Board license, the Revenue license, and the local license in whichever municipality the work sits in.
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Delaware is unusual in that the state itself runs a plumbing permit and inspection program rather than leaving permits entirely to counties and cities. The Division of Public Health operates the Plumbing Permit and Inspection Program, whose mission is to carry out and enforce the Delaware Plumbing Code, based on the 2018 International Plumbing Code with state amendments. The program inspects and permits plumbing installations statewide except where there are local jurisdictions with their own programs. Permits are issued to Delaware licensed plumbers, or to homeowners whose homes are owner occupied and not for sale or lease. The Division of Public Health charges a $100 fee for plumbing permits, payable by check or money order only. State residential permits are one time permits and must be secured 24 hours before work starts. Where a local jurisdiction runs its own plumbing program, contractors and homeowners are told to contact that local or county office instead. Title 24 confirms the split. Section 1832 provides that nothing in the chapter limits the ability of any county, municipality or other governmental entity to adopt and enforce plumbing, HVACR or fuel gas codes. For a plumbing contractor working across Delaware that means checking, per address, whether the job falls under the state program or a municipal one, because the permit application, the fee and the inspector all change. The state program takes general inquiries at 302-744-1220, with separate contacts for Kent and Sussex counties.
Wilmington adds a full layer of its own and it is the heaviest local requirement in the state. The city's plumbing code amendments provide at section 109.2.2(a)(1) that no individual shall engage in the business of plumbing in the city unless licensed as a master plumber, with an annual city master plumber license at $25.00, and section 109.2.3 sets a city examination fee of $50.00. Section 108.1.1 makes it unlawful for any person to work as a registered plumber in the state of Delaware and City of Wilmington unless that person has received a Certificate of Registry. Section 106.3.1.1 provides that plumbing work shall not be commenced until a permit has been issued by the Department of Licenses and Inspections, and that new piping additions to an existing piping system and the addition of any fixtures require a permit. There is a bond. Section 109.2.5 requires the person, firm or corporation to execute and deliver to the commissioner a good and satisfactory surety bond in the sum of $3,000.00. There is an insurance minimum. Section 106.7 requires a licensed master plumber to produce proof of liability insurance at the time of renewal of the plumbing license, at $300,000.00 for bodily injury and $100,000.00 for property damage each year. On top of the trade side, the city business license application prices a Plumbing Contractor license under code 1007 at $200.00, requires that plumbing, heating, air conditioning and mechanical contractors take the required tests and receive a Trade License from Licenses and Inspections before a business license is issued, and requires a copy of the current State of Delaware Business License with every application.
The Division of Professional Regulation publishes a public license lookup through DELPROS, and it covers every board the Division administers, including the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners. Anyone can search it without an account, and a license detail page returns the licensee record for that credential. Because Delaware licenses the individual rather than the company, a homeowner searching your company name in DELPROS may get nothing back even when the business is fully compliant. That is worth designing around. Put the licensed master plumber's name and license number on the estimate and on the website, so the customer has a term that actually resolves. The state has already done half the work for you by requiring the license number in three inch letters on the truck under 24 Del. C. 1806(a)(12), so the number a customer reads in a driveway is the number that verifies online. Customers verifying a Delaware plumbing company should really check three things, not one. The Board license through DELPROS confirms the person may perform plumbing services. The Division of Revenue business license confirms the company is registered to do business and pay gross receipts tax. In Wilmington, the city trade license and Certificate of Registry confirm the company may work inside the city. A contractor who can point at all three in a single paragraph on a service page answers the question before the customer asks it. Complaints against a licensee go to the Division's Investigative Unit.
Sourcesdelpros.delaware.gov 1dpr.delaware.gov 2delcode.delaware.gov 3revenue.delaware.gov 4wilmingtonde.gov 5
These are common details other guides publish about Delaware, but we could not verify them from the agency source. Confirm them directly before relying on them.
Yes. The Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, under the Division of Professional Regulation, licenses master plumbers statewide under 24 Del. C. Chapter 18.
Both, at two agencies. The Board licenses the individual master plumber. The Division of Revenue issues the business license every contractor conducting business activity in Delaware must obtain, at $75 renewable annually by December 31.
No. The Board issues Master Plumber, Master HVACR and Master Restricted HVACR. Chapter 18 carries no journeyperson plumbing license. A Journeyman Certificate functions as an input to licensure and shortens the required experience.
Two years of supervised work experience after receiving a Journeyman Certificate, or seven years of supervised work experience without one, plus the Apprenticeship By-Pass Exam at a minimum of 70 percent.
ProV Exam, the Division's external testing vendor. You apply through DELPROS first, and ProV contacts you to schedule after Board approval. The passing score is 70 percent and the exam is offered at least quarterly.
Applicants who do not pass after three attempts must reapply as a new applicant and may not reapply until one year has passed from the date they last took the examination.
The application fee is $173 for a Plumber license, and the same for Master HVACR and Master Restricted HVACR. A temporary plumber or HVACR license is $40. The renewal amount is given at the time of renewal.
October 31 of even numbered years. Late renewal is possible for up to one year with a late fee equal to 50 percent of the renewal fee. After a year the license terminates and you reapply as a new applicant.
Five hours of approved continuing education each renewal period, completed by June 30 of the renewal year. The first renewal is prorated to 0, 3 or 5 hours depending on when the license was issued.
Connecticut, Iowa and Maryland are treated as substantially similar and need no experience documentation. Fourteen other named states, including Ohio, Florida, New Jersey and Virginia, require proof of at least seven years of practice after licensure as a Master.
Under 24 Del. C. 1806(a)(12), the words Licensed Plumber and the assigned license number, in not less than 3-inch letters and numbers, on the vehicles used in the performance of the work.
Under 29 Del. C. 8735(s), no more than $250 for a first occurrence, and up to $1,000 per day for every day the unlicensed practice occurs after an admission or hearing, with possible referral for criminal prosecution.
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