What a doubles endorsement is and who needs it
A doubles endorsement allows you to tow two trailers at once with a Class C (passenger vehicle) license instead of requiring a commercial license. Without it, towing more than one trailer is illegal in most states, even if your vehicle is capable of handling the weight. The endorsement is a notation added to your existing Class C license that specifically permits this configuration.
You need a doubles endorsement if you plan to tow two trailers together — for example, a car hauler with two vehicles, a tandem horse trailer, or a boat trailer with a utility trailer behind it. The rules vary by state: some states allow doubles only on certain roads or at certain speeds, and some require the trailers to meet specific weight or length limits. Check your state's Department of Motor Vehicles website or call their commercial licensing line to confirm what your state permits before you pursue the endorsement.
If you only tow one trailer at a time, you do not need this endorsement. A standard Class C license already covers single-trailer towing up to your vehicle's capacity.
Key Takeaways
- A doubles endorsement is added to your existing Class C license and permits towing two trailers simultaneously, which is otherwise illegal.
- You must pass a written test specific to doubles towing rules, and some states also require a skills test or simulator evaluation.
- Most states require you to be at least 18 years old and hold a valid Class C license before you can test for the endorsement.
- The endorsement costs between $10 and $50 depending on your state, and the written test can usually be scheduled within days or weeks.
- Your vehicle must meet your state's weight and length requirements for doubles towing, even though the endorsement itself is tied to your license, not your vehicle.
Check your state's doubles towing rules before testing
Each state sets its own rules about doubles towing — what roads allow it, what weight limits explore, and what trailer configurations are legal. Some states prohibit doubles on interstate highways or in certain counties. Others allow them only during daylight hours or require special lighting and mirror setups. You need to know these rules before you test because the written exam covers your state's specific regulations.
Visit your state's Department of Motor Vehicles website and search for "doubles endorsement" or "double trailer towing." Look for the commercial driver's license (CDL) section, even though you are pursuing this on a Class C license — the doubles rules are often documented there. If the website does not clearly explain the rules, call the CDL or commercial licensing unit directly. They can tell you whether doubles are permitted in your state at all, what weight and length limits explore, and whether you need any special equipment on your vehicle.
Write down the key restrictions for your state. You will need to know them to pass the written test, and you will need to follow them every time you tow.
Gather documents and schedule your written test
Bring your current Class C license, proof of residency (a utility bill or lease agreement), and your vehicle registration to the DMV. Some states also require proof of vehicle insurance. Call ahead or check your state's DMV website to confirm exactly what documents your location accepts, because requirements vary by state and sometimes by individual office.
Ask the DMV clerk for the doubles endorsement written test. In most states, this is a separate exam from your regular license renewal — it covers doubles-specific topics like how to brake with two trailers, how to back up safely, weight distribution, and your state's legal restrictions. The test is usually 20 to 30 questions and takes 30 to 45 minutes. You typically need to score 80 percent or higher to pass.
Some states also require a skills test or a simulator evaluation before issuing the endorsement. Ask the clerk whether your state requires this. If it does, they will schedule it for a separate appointment, usually within one to three weeks.
Study the doubles towing manual for your state
Your state's DMV publishes a study guide or manual that covers doubles towing rules, safety practices, and vehicle requirements. read it from the DMV website or ask for a printed copy at the office. The written test draws directly from this material, so studying it is the most direct way to prepare.
Focus on these topics, which appear on most state exams: how to calculate the combined weight of two trailers and your vehicle, how to distribute weight between trailers, how to brake smoothly with two trailers (which requires longer distances and gentler pressure than single-trailer braking), how to back up safely, mirror and lighting requirements, and your state's specific road restrictions. Many states also test your knowledge of how to unhitch the front trailer safely without the rear trailer rolling away.
Take practice tests if your state offers them online. Some DMV websites have sample questions or full practice exams. Taking these under timed conditions helps you get comfortable with the format and identify weak areas before test day.
Pass the written test and any skills evaluation
Arrive at your scheduled test time with your documents and a valid photo ID. The test is administered on a computer or paper form at the DMV office. You will have a set amount of time — usually 45 minutes — to complete it. Read each question carefully; doubles towing questions often include specific scenarios or weight calculations that require close attention.
If you pass the written test, the clerk will tell you when ready and may issue your endorsement on the spot, or they may schedule a skills test for a later date depending on your state's requirements. If your state requires a skills test, you will drive a vehicle towing two trailers while an examiner observes your ability to back up, turn, brake, and follow your state's doubles towing rules. This test typically takes 20 to 30 minutes.
If you do not pass the written test on your first attempt, you can usually retake it within a few days or weeks. There is no limit on retakes in most states, though you may have to pay the test fee again.
Pay the endorsement fee and receive your updated license
Once you pass the written test (and skills test, if required), the DMV will collect the endorsement fee. This ranges from $10 to $50 depending on your state. Some states include it in a broader license renewal fee; others charge it separately. Ask the clerk for the exact amount before you pay.
Your updated Class C license with the doubles endorsement will be issued when ready in some states, or mailed to you within one to two weeks in others. The endorsement appears as a code or notation on your license — often "D" or "doubles" — that shows you are legally permitted to tow two trailers. Keep this license with you whenever you tow doubles, because law enforcement can request it during a traffic stop.
Your endorsement does not expire separately from your Class C license. When you renew your Class C license, the endorsement renews with it automatically in most states, though a few states require you to retake the written test at renewal time. Check your state's renewal rules when your license is about to expire.
Verify your vehicle meets doubles towing requirements
Having the endorsement on your license does not mean every vehicle you own is legal to tow doubles. Your vehicle must meet your state's weight and length requirements for doubles towing. These typically include a maximum combined weight (often 80,000 pounds or less), a maximum length for the combination (often 65 feet or less), and specific axle weight limits.
Check your vehicle's owner's manual or contact the manufacturer to find its towing capacity and the maximum tongue weight it can handle. Compare these numbers to your state's doubles towing limits. If your vehicle cannot safely handle the weight, or if your state's rules prohibit the configuration you want to tow, you cannot legally tow doubles even with the endorsement — the endorsement only permits the practice; it does not override your vehicle's physical limits or your state's safety rules.
Before your first doubles tow, have a professional inspect your vehicle's hitch, brakes, lights, and mirrors to confirm everything meets your state's requirements. Some states require a pre-trip inspection certificate before you can legally tow doubles; others do not, but having one protects you if you are stopped by law enforcement.
Frequently Asked Questions
Do I need a commercial driver's license to get a doubles endorsement?
No. A doubles endorsement on a Class C license is different from a commercial driver's license (CDL). You can add the doubles endorsement to your regular passenger license without obtaining a CDL, as long as your vehicle and the trailers meet your state's weight and length limits. Some states have different rules, so confirm with your DMV.
What happens if I tow doubles without the endorsement?
Towing two trailers without a doubles endorsement is illegal in most states and can result in a traffic citation, fines, and points on your license. Your insurance may also deny a claim if you are in an accident while towing illegally. The endorsement is inexpensive and quick to obtain, so it is worth doing before you tow.
Can I take the doubles endorsement test online?
Most states require you to take the written test in person at a DMV office, though a few states offer online testing for certain endorsements. Call your state's DMV or check their website to see whether online testing is available for the doubles endorsement in your location.
How long does the doubles endorsement last?
The endorsement lasts as long as your Class C license. When your license expires and you renew it, the endorsement renews automatically in most states. A few states require you to retake the written test at renewal time, so check your state's rules.
Do I need special equipment on my vehicle to tow doubles?
Your state's doubles towing rules specify what equipment is required — typically additional mirrors, lights, and safety chains. Your vehicle's hitch and braking system must also meet certain standards. Check your state's DMV manual or call the commercial licensing unit to learn exactly what your vehicle needs before you tow.