The F endorsement lets you haul hazardous materials in a tank vehicle in Tennessee

The F endorsement on your Tennessee commercial driver's license means you are permitted to drive a tank vehicle carrying hazardous materials. This is different from a regular hazmat endorsement — the F specifically covers the tank vehicle itself, the equipment that holds and transports liquids, gases, or other hazardous cargo.

You cannot get an F endorsement on its own. Tennessee requires you to hold an H endorsement (hazardous materials) first. Once you have the H, you can add the F. Together, they allow you to legally transport hazmat in a tank truck, tanker trailer, or similar vehicle.

If your job involves hauling fuel, chemicals, milk, or any other liquid or gas in a tank vehicle, your employer will likely require you to have both endorsements. Without them, you cannot legally operate that equipment, even if you hold a valid CDL.

Key Takeaways

  • The F endorsement covers tank vehicles only and must be added to an existing H (hazmat) endorsement.
  • You must pass the tank vehicle knowledge test at a Tennessee Driver Services office to add the F endorsement.
  • The F endorsement does not expire separately — it renews with your CDL when your license comes due.
  • Tank vehicle experience or training from your employer can help you prepare for the test, but is not required by the state.

How the F endorsement differs from the H endorsement

The H endorsement is the hazardous materials endorsement. It means you have passed a background check and a knowledge test about hazmat safety, labeling, and regulations. The H endorsement allows you to transport hazardous cargo in any vehicle — a flatbed, a box truck, a regular tractor-trailer.

The F endorsement is specific to the vehicle type. It covers tank vehicles — the equipment itself, how to load and unload them, how to inspect them, and the special rules for moving liquids and gases under pressure. You need the F only if you are driving a tank vehicle. If you haul hazmat in a regular truck bed or enclosed box, you need only the H.

Many drivers hold both H and F. Some hold only H because their job does not involve tank vehicles. You cannot hold F without H.

Steps to add the F endorsement to your Tennessee CDL

First, confirm you already hold an H endorsement on your current CDL. If you do not, you must get the H before you can add the F. The process for adding H is separate and comes first.

Once you have the H, visit any Tennessee Driver Services office with your current CDL and a completed process. You will take the tank vehicle knowledge test at that office. The test covers tank vehicle inspection, loading and unloading procedures, emergency response, and safe operation of pressurized cargo equipment.

You do not need to schedule the test in advance. Walk-in testing is available during regular office hours, though wait times vary by location. Bring your CDL, a valid form of identification, and any required fees. After you pass the test, the F endorsement is added to your license on the spot or within a few days, depending on the office.

What the tank vehicle knowledge test covers

The Tennessee tank vehicle test has 20 questions. You must answer at least 16 correctly to pass. The test covers the equipment itself — how to inspect a tank vehicle before driving, what to look for in the tank, piping, valves, and safety devices. You will see questions about proper loading and unloading procedures, including how to ground a tank to prevent static buildup.

The test also covers safe operation — how speed and braking affect a partially filled tank, why you cannot use cruise control in a tank vehicle, and how to handle emergencies like a leak or rollover. You will answer questions about hazmat regulations specific to tank transport and what to do if you are stopped by law enforcement.

Study materials are available free from the Tennessee Department of Safety and Homeland Security. The CDL manual includes a tank vehicle section. Many drivers also study materials from their employer or from commercial driver training schools, though formal training is not required by the state.

Fees and renewal for the F endorsement

Tennessee charges a fee to add the F endorsement to your CDL. The exact amount varies and can change, so confirm the current fee when you visit a Driver Services office. The fee is separate from any CDL renewal fees if your license is also coming due.

The F endorsement does not have its own expiration date. It renews automatically when your CDL renews. If your CDL is valid for five years, your F endorsement is valid for the same five years. When you renew your CDL, you do not have to retake the tank vehicle test unless Tennessee changes the test or you let your CDL expire.

If your CDL expires and you do not renew it within a certain grace period, you may have to retake the tank vehicle test when you reapply. Check with your local Driver Services office about the grace period rules.

When you might need the F endorsement

Common jobs that require an F endorsement include fuel delivery, propane transport, milk hauling, chemical transport, and any role involving a tank truck or tanker trailer. Your employer will tell you during hiring whether the F is required for the position.

Some employers provide or pay for training to help you pass the tank vehicle test. Others expect you to study on your own. Either way, the test itself is administered only by Tennessee Driver Services — no private testing center offers it.

If you are already driving a tank vehicle without the F endorsement, you are operating illegally. Contact your employer and a Driver Services office right away to add it. The penalty for driving without the required endorsement can include fines and suspension of your CDL.

Frequently Asked Questions

Do I need the F endorsement if I only haul hazmat sometimes?

You need the F endorsement only if you drive a tank vehicle. If you haul hazmat in a regular truck bed or box truck, you need only the H endorsement. If your job involves both — sometimes a tank vehicle, sometimes not — you need both H and F to be legal in either situation.

Can I take the tank vehicle test without an H endorsement?

No. Tennessee requires you to hold an H endorsement before you can add the F. If you do not have the H yet, you must pass the hazmat test first, then return to add the F.

How long does it take to get the F endorsement added?

If you pass the test on your first try, the endorsement is usually added the same day or within a few business days. The test itself takes about 15 to 30 minutes. Wait times at the Driver Services office vary by location and time of day.

What happens if I fail the tank vehicle test?

You can retake the test. There is no waiting period between attempts in Tennessee, though you may have to pay the test fee again. Most people pass on the second or third attempt after studying the CDL manual tank vehicle section.

Does the F endorsement cost extra when I renew my CDL?

The F endorsement renews with your CDL at no additional charge. You pay the standard CDL renewal fee, which covers all your endorsements. You do not retake the tank vehicle test unless your CDL expires and you wait too long to renew.