AZ vs DZ Licence in Ontario: Which One Do You Need?

If you are comparing AZ vs DZ licences in Ontario, start with the vehicle you want to drive. A tractor-trailer hauling freight and a straight truck delivering concrete can both have air brakes, but their drivers need different vehicle-class authority.

The biggest difference is the trailer. Class D covers qualifying heavy trucks and combinations with a towed vehicle no heavier than 4,600 kg. Class A covers heavier trailer combinations. The Z in both names is the air brake endorsement.

For firefighter applicants, commercial drivers and utility operators, choosing the right route can save unnecessary training costs and help you prepare for the work ahead. Here is how to make that decision.

These examples describe common configurations. The actual weight, configuration, brakes and licence conditions determine the authority required. Check Ontario’s truck licensing guidance for your vehicle.

DZ combines an Ontario Class D licence with a Z air brake endorsement.

Class D applies to qualifying trucks exceeding 11,000 kg gross weight or registered gross weight. It also covers qualifying combinations over that threshold where the towed vehicle does not exceed 4,600 kg. It includes Class G driving authority.

That makes DZ relevant to many straight trucks used for construction, deliveries, municipal services and emergency response. A heavy dump truck with air brakes may fit this category, for example.

However, “dump truck” is not a complete licensing answer. Add a heavier trailer and the required class can change. Likewise, a utility fleet can contain vehicles requiring different licences.

If DZ fits your goal, our step-by-step Ontario DZ licensing guide explains the application, medical report, testing and training process.

AZ combines Class A vehicle authority with the Z endorsement. Class A is relevant when the towed vehicle exceeds 4,600 kg, including typical highway tractor-trailer combinations.

Full Class A also covers Class D and G vehicles. However, it does not automatically authorize every vehicle on the road: passenger buses and motorcycles have separate licensing requirements.

An AR licence, or Class A with condition R, has restrictions. DriveTest states that restricted Class A drivers cannot operate a motor vehicle pulling double trailers or a trailer with air brakes.

The test vehicle matters. For a full AZ test, DriveTest requires an appropriate truck/tractor and trailer combination with full air brakes on both units. A different configuration can result in restricted Class A authority.

Before paying a school, ask which licence and restrictions its program and test vehicle are designed to produce. Read DriveTest’s commercial road-test requirements alongside the school’s description.

Consider three ordinary commercial-driving examples:

These examples assume the other licensing and legal operating requirements are met. They do not determine permitted payloads, axle weights or towing capacity. A driver’s licence and a vehicle’s legal operating limits answer different questions.

For the licence definitions, use the MTO Truck Handbook’s A and D requirements.

Z is the Ontario air brake endorsement in both combinations. The vehicle class still determines what you may drive.

A Z endorsement added to a G licence does not provide Class D or Class A authority. Similarly, a Class D licence without Z does not authorize a truck equipped with a system requiring the endorsement.

Air brake knowledge includes compressors, reservoirs, governors, service brakes, spring brakes and inspection procedures. AZ practical testing also includes the trailer air brake system; the other licence-class versions do not include that trailer component. Our guide to passing the Ontario Z air brake test explains the written and practical preparation for each pathway.

Start building your understanding with our Ontario Air Brake Practice Test. For pressure limits and the conditions attached to them, use the Ontario air brake PSI study guide. Continue hands-on preparation with a qualified instructor.

Ontario’s full Class A pathway requires mandatory entry-level training, commonly called MELT. Class D does not have that same requirement.

Ontario currently describes MELT as at least 103.5 hours of instruction. Training must be completed and recorded before the full Class A road test where the requirement applies. Moving from DZ or AR to full AZ does not automatically remove it.

Class D still requires preparation for medical and vision standards, knowledge testing, inspection and safe on-road operation. The absence of Class A MELT does not make a beginner ready to drive a heavy truck without instruction.

Use the official Class A training guidance when comparing programs. Ontario is developing further truck-training requirements, so confirm the rules applying to your actual start and test dates.

DriveTest advises that, from January 1, 2027, full Class A road-test applicants must have held G or higher for at least six months. The amending regulation sets out the qualifying experience and alternative provisions.

If your training crosses into 2027, confirm eligibility before paying for a test date. Do not assume this Class A change applies to Class D.

Start with your target department’s current posting. Where it asks for an unrestricted DZ licence, completing DZ addresses that stated licensing requirement. Check when it must be held: application, interview, conditional offer or another specified deadline.

AZ may make sense if you also want a commercial driving career involving heavy trailers. It is a larger decision than simply collecting another qualification. Compare the additional training with your actual career plans and ask the municipality how it treats higher or equivalent classes.

A licence alone does not replace apparatus-specific training or department authorization. Different fire vehicles and trailer arrangements can need different authority.

For the broader hiring pathway, see our Ontario firefighter career guide.

Use the equipment listed in the job description as your starting point:

Licensing eligibility and employability are separate. Employers and insurers may also assess driving experience, abstracts, practical skills and familiarity with their equipment. Neither licence guarantees a job or salary.

The larger cost difference usually comes from training and vehicle access, rather than the basic examination fees.

DriveTest currently lists a commercial knowledge test at $23.75, a commercial road test at $99, and the under-65 knowledge-and-road package at $122.75. Z knowledge is $16; the standalone Z practical is $50. Combined commercial road/Z practical arrangements affect which fees apply.

Compare current DriveTest fees with an itemized school quote. Ask about:

Full AZ training generally requires a greater time commitment because of MELT. A lower advertised price is not useful if it omits essential lessons, testing or truck access. Compare like-for-like inclusions.

Full Class A includes Class D authority, and Z covers the applicable air brakes. Check your individual licence conditions and the employer’s equipment-training requirements.

Yes, by meeting the Class A requirements that apply to you, including knowledge testing, training and the appropriate road test. DZ experience does not automatically exempt you from MELT or grant Class A authority.

Not through the ordinary Ontario application pathway. You need full G or an eligible higher licence. Check the additional Class A experience requirement for road tests from January 2027.

Ontario’s Class A/AR transmission rules can restrict which Class A/AR vehicles you may drive. DriveTest states that this restriction does not apply when operating lower-class vehicles such as D or G. Discuss the test transmission with your instructor before booking.

For Class D road rules and truck knowledge, try the Class D Practice Test. For Z, use the Air Brake Practice Test. If you need both for DZ, start with the Ontario DZ Practice Test.

Class A applicants should follow the full Class A handbook and training curriculum; Class D practice alone does not cover the complete AZ pathway.

Choose the licence that fits the vehicles you intend to operate, your target jobs and your training budget. Confirm the requirements, compare instruction and begin knowledge study before your testing deadline approaches.

Preparing for DZ? Try free Ontario DZ practice questions and identify which Class D and air brake topics need more attention.

Reviewed October 19, 2026. This comparison concerns ordinary Ontario commercial licensing; special exemptions and RV-specific pathways can differ. Confirm your requirements with Ontario, DriveTest and your training provider.