C-61/D-56 Trenching Only Contractor License in California
The C-61/D-56 Trenching Only license is for contractors whose business is digging trenches for foundations, pipelines, conduit and related work.
Quick answer
The C-61/D-56 Trenching Only Contractor license lets you contract for trenching only work in California on jobs that require a building permit, use employees, or total $1,000 or more in labor and materials. To qualify you need four years of journey-level experience in the last ten years, an approved CSLB application, and a passing score on the Law & Business exam. The D-56 is a category of the C-61 Limited Specialty classification, so there is no trade exam.
- Classification
- C-61/D-56 Trenching Only Contractor
- License type
- Limited Specialty (C-61)
- Exams
- Law & Business exam only (no trade exam)
- Experience
- 4 years at journey level or higher, within the last 10 years
- Application fee
- $450 (original application)
- Initial license fee
- $200 sole owner · $350 other entities
- Contractor bond
- $25,000
- Workers’ compensation
- Workers’ comp certificate, or exemption if no employees
What a D-56 Contractor Can Do
CSLB definition: A trenching contractor is a limited specialty contractor whose contracting business is trenching only for foundations, pipelines, conduit and related trenching work. (CSLB definition for this C-61 subcategory, approved by the Board as policy; condensed. See the full text on CSLB.ca.gov.)
Typical D-56 work
- Trenching for foundations and footings
- Trenching for pipelines and utility lines
- Trenching for electrical conduit
- Related trenching work on construction projects
Needs a different license
- Installing the pipe, conduit or utilities in the trench (for example C-34, C-36 or C-10)
- General grading and excavation (C-12 or Class A)
- Pouring foundations (C-8)
California law requires excavators to contact 811 at least two working days before digging so underground lines can be marked. Expect this topic in your Law and Business preparation.
D-56 License Requirements
CSLB uses the same core requirements for every classification. For the D-56, the qualifying individual (you, or the RMO/RME for a company) must:
- Be at least 18 years old.
- Have at least four full years of experience in trenching only work within the last ten years, as a journeyman, foreman, supervising employee, contractor or owner-builder.
- Have that experience certified by someone with firsthand knowledge of your work, such as an employer, foreman, fellow journeyman, building inspector or homeowner.
- Pass the Law & Business exam, and complete CSLB’s asbestos open-book exam.
- Complete Live Scan fingerprinting and CSLB’s background review.
You may receive up to three years of credit toward the four-year requirement for technical training, apprenticeship or related education, but at least one year must be practical experience. There is no education requirement to get a California contractor license.
How to Get a D-56 License: Step by Step
- Confirm your classification. Compare your work with the D-56 scope above and the related classifications below.
- Document your experience. Gather proof of four years of trenching only experience and line up a qualified person to certify it.
- Apply to CSLB. Submit the original application with the $450 fee. CSLP can help prepare your application so it is not returned for corrections.
- Get fingerprinted. Complete Live Scan once CSLB accepts your application.
- Study and pass your exam. Pass the Law & Business exam. It is multiple choice.
- Meet issuance requirements. File your $25,000 contractor bond, workers’ compensation information, asbestos open-book exam and the initial license fee.
How Much Does a D-56 License Cost?
These are CSLB’s published fees. Bond premiums, insurance and exam preparation are separate costs that depend on your situation.
| Item | Cost |
|---|---|
| Original application (one classification) | $450 |
| Initial license fee | $200 sole owner · $350 non-sole owner |
| Live Scan fingerprinting | $32 DOJ + $17 FBI + site rolling fee |
| Contractor bond | $25,000 bond (you pay an annual premium) |
| Active renewal (every two years) | $450 sole owner · $700 non-sole owner |
| CSLP online exam prep | From $595 (Fast Track) |
Fees verified on CSLB’s fee schedule in November 2026. CSLB can change fees, so confirm before you apply.
How to Prepare for the Law & Business Exam
CSLP has prepared California contractors for their CSLB exams since 2013. Our D-56 preparation covers the Law & Business exam with:
- Updated 2026 online classes in English and Spanish
- Weekly live online classes with Q&A
- Online law and trade books with practice questions
- Per-chapter practice quizzes (Plus and Premium)
- Application processing help
- Optional 2-day in-person bootcamp
Study 100% online at your own pace with online courses, or finish with an intensive in-person CSLB exam bootcamp at a CSLP location.
Content reviewed against CSLB sources: November 2026
- CSLB: D-56 Trenching Only Contractor classification
- CSLB: C-61 Limited Specialty and its D categories
- CSLB: Qualifying experience for the examination
- CSLB: Issuing my license (bond, workers’ comp, fees)
- CSLB: List of all fees
Online California Contractor License Courses
Prepare for your California CSLB Law & Business and Trade exams with flexible online contractor license courses designed for real working contractors. Choose from three study plans with 24/7 online access, bilingual support, weekly live classes, and expert guidance throughout the licensing process.
Fast Track
$595
- 2026 Updated Classes
- Online Law Book
- Online Trade Book
- Weekly Live Online Classes
- Application processing
- 24/7 Online Access
Plus
$1,395
- Everything in “Fast Track”
- Plus:
- Law & Business Flash Cards
- Per Chapter Practice Exams
- Extended Study Time
- Physical Law & Trade Books
Premium
$1,595
- Everything in “Plus”
- Plus:
- Business Launch Checklist
- Digital Business Card ($200 value)
- Double Study Time vs. “Plus”
All Online Course Packages Include:
Bilingual Lessons
English & Español
Weekly Live Classes
Online Only
Law & Trade Books
English & Español
Proven Results
20,000+ Graduates
D-56 License FAQs
What can I do with a D-56 license?
The C-61/D-56 Trenching Only license is for contractors whose business is digging trenches for foundations, pipelines, conduit and related work. See the official CSLB definition above for the full legal scope.
How much experience do I need for a D-56 license?
You need at least four full years of journey-level experience (or as a foreman, supervisor, contractor or owner-builder) in trenching only work within the last ten years. Up to three years can be credited for qualifying education, apprenticeship or technical training.
What exams do I take for the D-56 license?
D-56 is a category of the C-61 Limited Specialty classification, so applicants take only the Law & Business exam. There is no D-56 trade exam. All new applicants also complete CSLB’s asbestos open-book exam.
How much does it cost to get a D-56 license?
CSLB charges a $450 application fee and an initial license fee of $200 for a sole owner or $350 for other business types. You also need a $25,000 contractor bond, fingerprinting fees and, if required, workers’ compensation insurance. CSLP online exam prep starts at $595.
Can a D-56 contractor install pipe in the trench?
No. CSLB defines the D-56 as trenching only. Installing pipelines, conduit or utilities requires the classification for that work, such as C-34 Pipeline, C-36 Plumbing, C-10 Electrical or Class A.
Can I study for the D-56 exam online or in Spanish?
Yes. CSLP’s online courses include bilingual lessons in English and Spanish, weekly live online classes and law and trade books. You can also join an in-person bootcamp at select CSLP locations. Compare course options.