What is the C-61/D-21 Machinery License?

A conveyor belt system typically found in a factory. has boxes on top being transported

C-61/D-21 Machinery and Pumps Contractor

The C-61/D-21 machinery License is the classification required in the state of California for anyone looking to contractor for projects involving machinery and pumps where the cost of labor and materials exceeds $500.

C-61 Limited Specialty Classification

The C-61 Limited Specialty License is an umbrella term for all licenses that may fall under a more obscure category of construction work. They cover specific areas of construction and construction-related tasks.

If your skill set or business is limited to one particular portion of trade work, you could obtain a C-61 limited specialty license to contract over $500 for your services legally.

Typical activities associated with the D-21 Machinery License

The D-21 contractor license covers a wide range of services associated with a variety of commonly used machinery.

While services may vary based on expertise, typically duties include:

  • Design, fabrication, installation and repair of various types of machinery
  • Installation and repair of automatic car wash equipment 
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    Repair of auto body paint finishing booth equipment
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    Handicap lifts and overhead factory cranes
  • Design and installation of conveyor belt systems
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    Load dock levelers and dumb waiters
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    Trouble shooting and repair of garment conveyors
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    Maintaining personal and job-site safety
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    Preparing bids, making invoices and accounting
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    Site evaluation and cost calculations
an automatic car wash system. another of the types of machinery that D21 contractors specialize in

Car wash machinery is included under the C61/D21 license

Functioning machinery is often a vital aspect of industrial businesses that depend on assembly line production to meet quotas and fulfill orders.

As we move closer to the age of artificial intelligence and an increased dependence on robots, services offered by machinery pumps contractors will become invaluable.

Subcontractor License

Due to the nature of the trade, machinery pumps contractors typically work directly with businesses that depend on some type of machinery for their bottom line. 

In a construction setting, a General Engineering Contractor may hire a D-21 machinery Contractor specifically for their expertise.

A contractor holding the D-21 license may also be hired for their equipment.

As a result, a general engineering contractor ensures that this phase of the project is executed correctly.

Learn more about the General Engineering Contractor License!


Logo of the CSLB. illustration includes a paint brush, hand saw, cement truck and the letters CSLB above in white

The Contractors State License Board (CSLB) is the governing body for all contractors in the state of California. Their sole responsibility is to protect the consumer public. 

They ensure that anyone charging over $500 for construction services is qualified and registered with the state.

The C-61 / D-21  Machinery contractor license is issued to contractors by the CSLB. 

D-21 Machinery License Requirements

To get the D-21 contractor license individuals must prove a minimum of 4 years journeyman level experience and pass a law exam.

To qualify for an exam date you must meet the the following requirements:

  • Be at least 18 years of age
  • Have a valid Driver's License or USA Issued Identification
  • Have a Social Security or ITIN #
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    Not Currently be on probation or parole

You must also have:

  • 4 Years Journey Level Experience 
  • A Qualifying Individual to sign off on your experience
  • A way to prove your experience if the state asks for documentation

What is journey level experience?

A dock leveler commonly used to unload shipping containers. dock levelers are an area of expertise covered under the machinery license

Journeyman level experience means that you have worked unsupervised full time for a Factory, General A contractor, or someone that holds the D-21 License.

  • A journeyman can perform all of the duties associated with his or her trade.

The CSLB will want to see four full-time years over the last ten years. The years do not need to be consecutive, but they do need to be four years in total. 

Signature of a Qualifying Individual

The following people may act as a Qualifying Individual when applying for the machinery license

  • Licensed General Engineering Contractor
  • C-61 / D-21 License Holder
  • Former Supervisor (within the last 10 years)
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    Fellow Employee (within the last 10 years)
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    Business Associate
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    Fellow Journeyman
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    Union Representative

How to fill out the Contractor License application

In addition, your Qualifying Individual will need to provide a brief but detailed description of your knowledge and skillset.

The way this description is written is critical to whether or not your application gets accepted. For example: 

“Eduardo knows how to fix conveyor belts” is not detailed enough.

 The CSLB will want to see something like:

"Eduardo has trouble shot conveyor belt systems of all kinds, conducted diagnostics, installed and repaired new systems" etc.

Most importantly, the description written by your qualifying individual has to include the core skills required for the contractors license.

Work experience for the Contractor License

A white car being raised up by a machine

You must be prepared to submit documentation supporting the experience you claim to have. The Contractors State License Board gives you a few ways that you can prove your experience which include:

  • Tax Returns
  • Check Stubs
  • Contracts
  • Material Order Invoices or Receipts

The CSLB  receives thousands of applications per month so there is a good chance they won’t document your experience but if you are one of the applicants that get reviewed you will need to be ready to submit something. 

The CSLB does not accept pictures of projects.

Application Processing, Fees and Criminal History

The time it takes to get your application processed and assigned a test date fluctuates throughout the year.

Typically you can expect:

  • 6-8 Week Application Processing Time
  • 3-4 Week wait for an Exam date

I have seen some situations where applicants got their test date sooner and some where they got their test date much later.

The most common reasons your application would get held up are:

  1. Time of year (processing time slows down during the holidays) 
  2. Criminal History 
  3. Proving Experience
  4. Mistakes on your application 

Contractor License Fees

The Current CSLB fees are: 

Can you get a Contractors License with a Felony in California?

image shows black handcuffs and keys. it is very important to be honest about your criminal history when applying to the CSLB

Having a criminal record in no way stops you from getting a C-61/D-21 contractor License. I have personally helped guys with all types of criminal records obtain multiple licenses.

The key is to be honest on the application, even if the felony or misdemeanor happened years ago and even if it was expunged.

BE 100% HONEST ON THE APPLICATION, because they will see everything anyway when you do fingerprinting. The CSLB handles criminal records on a case by case basis.

Remember, their responsibility is to protect the public.

Typically the CSLB is most concerned with Fraud, Embezzlement and Forgery.

The Contractor License Exam

Contractor licenses are broken down into four categories:

1) A-General Engineering

2) B-General Building

3) C-Specialty classes

4) C-61 / D-Limited Specialty classes

Each category of license except the D-Limited Specialty license class requires that you pass a TRADE exam. C-61 Classification licenses do not have trade portions.

You must only pass a LAW exam. The exam is:

  • 115 Questions on Contractor LAW
  • 3 Hours to complete
  • Multiple choice, taken on a computer
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    Closed Book

The Law Examination is divided into eight major sections:

1. Business Organization (10%)

  •  Company organization
  •  Project organization

2. Business Finances (15%)

  • Cash management
  • Budget and planning
  • Taxes
  • Financial reporting

3. Employment Requirements (12%)

  • Employment regulations
  • Evaluation and record-keeping
  • Payroll

4. Bonds, Insurance, and Liens (10%)

  • Bonds
  • Workers’ compensation insurance
  • Liens and other remedies
  • Other insurance

5. Contract Requirements and Execution (23%)

  • Bidding
  • Cost control
  • Contracts
  • Payments

6. Licensing Requirements (8%)

  • Business license
  • Contractor’s license
  • Activity regulation

7. Safety (15%)

  • Training and reporting requirements
  • General safety
  • Hazardous/unknown materials

8. Public Works (7%)

  • Prevailing wage requirements
  • Bonding requirements
  • Insurance requirements

What is Contractor License LAW?

Recommended Resources

CSLB Test Locations

There are currently CSLB test locations in the following cities:

  • Sacramento 
  • San Bernardino 
  • San Diego  
  • San Jose
  • Berkeley 
  • Fresno 
  • Norwalk 
  • Oxnard
  • The CSLB will assign you a testing center based on your location 
  • The test is not available online 
  • The CSLB allows you to bring a pre-approved translator with you 
  • The CSLB will grant you 18 months after your application is accepted to pass the law test
  •  You must wait three weeks before retaking the state exam ($60 per retake)

California Contractors License Exam Prep

a pencil and wooden ruler laying on top of a construction blueprint. to get the C61/D21 machinery license you will need to pass a law exam
  • Getting the D-21 Machinery License  is a smooth process if you have the right information. 
  • It can be confusing to see un-familiar terms used to describe tools or job site practices. The Contractor LAW exam covers a number of different topics.
  • Questions are presented to you as if you are running a large scale remodeling business with multiple employees.
  • Being prepared and knowing what to study is the most important thing you can do in ensuring your success on the contractor license exam.

Machinery Apprenticeship

A home handicap chair lift connected to a wooden stair case

If you do not have the experience required to get the C-61/D-21 Machinery Contractor license, not to worry! 

Your journey begins here. Generally someone looking to become a contractor would want to look into an apprenticeship for find an experienced person to work with.

For a detailed explanation on this process, check out my article: Apprentice vs Journeyman!

Blueprint Reading Course

image of a black ruler and brown paper bad laying on top of a desk, blueprint reading is an important skill for contractors looking to get the machinery license

Learn Blueprint Reading!

Contractors working in factories installing various types of machinery and pumps should be able to read designs and symbols on construction blueprints. If installation or repair is part of a larger project, being able to execute their duties within the larger scope of the job is essential. 

Reading blueprints is an invaluable skill for all tradesman but can be especially important for elevated flooring contractors.

Check out our Free Blueprint Reading Course!

OSHA Certification

image of a contractors working high up on a steel beam. contractors looking to get the C-61/D-21 machinery license should look also into get an osha certification

Occupational Safety Hazard Association

Statistically, 21% of all work-related fatalities are in construction.

That equals about 1 and 5 worker deaths on average. In the construction industry, the leading cause of worker deaths is reported as falls, struck by an object, electrocution, and caught-in/between.

Working in factories can be dangerous, especially if your workers are not properly trained.

For employment within a factory environment typically it is a requirement that you have completed some level of OSHA training. Learn more about OSHA Training.


Becoming a licensed and bonded contractor can be a huge step up in your career if you are looking to start your own company or become an RMO for an existing firm!

The key is to take action and follow these steps from beginning to end. 

If you have found this article helpful feel free to drop a comment below and be sure to check back for updates!

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