Plumbing Contractor Permit Requirements in Wilmington, DE

1. EIN (Employer Identification Number)

   Required if you have employees or operate as an LLC or corporation. Free from the IRS.

   Official government source

   Free·Immediate (online application)

   Free

   Immediate (online application)

1. Delaware — No Sales Tax

   Delaware has no state or local sales tax. Instead, Delaware levies a Gross Receipts Tax on the seller of goods or provider of services, based on total receipts. Register with the Delaware Division of Revenue.

   Official government source

   Free (gross receipts tax registration)·Immediate (online)

   Free (gross receipts tax registration)

   Immediate (online)

1. Delaware Board of Plumbing, HVACR Examiners — Master Plumber License

   Plumbing contractors in Delaware must hold a Master Plumber License from the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners under the Division of Professional Regulation — not the Department of Labor. Applications are filed in DELPROS and require passing the state exam; see the Board's Master Plumber Licensure page for the current experience requirements.

   Official government source

   $173 (Plumber application fee, per DPR fee schedule)·4–8 weeks

   $173 (Plumber application fee, per DPR fee schedule)

   4–8 weeks

2. City of Wilmington Business License (Department of Finance, Wage/Business License Division)

   Businesses operating inside Wilmington must hold a City of Wilmington business license in addition to their State of Delaware business license. Applications are filed with the Department of Finance, Wage/Business License Division (302-576-2415), and a copy of the current State of Delaware business license must be attached. Fees are set per license-type code; air conditioning, plumbing, heating, mechanical and refrigeration contractors must first pass a trade test with the Department of Licenses and Inspections. Employers also pay a head tax of $15 per month for each employee above five.

   Official government source

   Set by license-type code (fee increase effective 1/1/2024): $200/year for most non-professional services (e.g. landscaping/tree services, beauty parlor/barber shop, day care centers, janitorial, pest control, photographers) and construction trades; $300 for professional services; $250 for retailers; $151 for a mobile food vendor; $50 branch license·1–3 weeks

   Set by license-type code (fee increase effective 1/1/2024): $200/year for most non-professional services (e.g. landscaping/tree services, beauty parlor/barber shop, day care centers, janitorial, pest control, photographers) and construction trades; $300 for professional services; $250 for retailers; $151 for a mobile food vendor; $50 branch license

   1–3 weeks

3. City of Wilmington Plumbing Permit (per project)

   A separate plumbing permit must be pulled from the City of Wilmington Department of Licenses and Inspections for each job inside city limits — New Castle County has no jurisdiction here. Inspections are required on completion. Plumbing contractors must also pass a City trade test with the Chief Plumbing Inspector before a Wilmington business license is issued, on top of the Delaware Division of Professional Regulation licence.

   Official government source

   $20 per craft used (plumbing counts as one craft), capped at $50 per job, plus the building permit fee of $12 per $1,000 of construction cost, per the City's published Development Review Process fee list·1–5 business days

   $20 per craft used (plumbing counts as one craft), capped at $50 per job, plus the building permit fee of $12 per $1,000 of construction cost, per the City's published Development Review Process fee list

   1–5 business days

Official Sources

• Delaware Department of Labor — Master Plumber License
• City of Wilmington Revenue Division

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