South Dakota treats a trailer as a separate registration problem rather than an accessory to the vehicle in front of it. The trailer carries its own title, its own plate and its own fee, and the county treasurer of your residence handles the filing. Two plate routes exist, and the one you take depends on the truck that pulls the load and on how the trailer was built. A buyer who assumes the trailer rides on the truck plate learns otherwise at the counter.
This page covers the county application, the annual trailer plate, the ten dollar identification plate and the assigned number route for a trailer built at home. It sets out the weight line that decides between the two plate types, along with the gross weight question that follows any tow vehicle. Fees here come from the state schedule, and the county treasurer applies that schedule to your own trailer record. Nothing on this page replaces the figure the clerk reads back to you at the window.
How to Register a Trailer in South Dakota
Form 1001 is the title and registration application, and for a trailer it is filed in the county where the applicant lives. The same sheet starts a title record and a plate order, so the county builds both from one filing. The trailer itself does not need to be present for the paper side of the work. Bring the ownership document, your identification and the weight figure, then let the clerk apply the schedule. A trailer bought in another county still goes through the office that serves your home address, since the filing point follows the owner rather than the seller.
- Start with Form 1001: the title and registration application covers a trailer and is filed in the county of your residence.
- Bring the ownership paper: a title signed over by the seller, or the manufacturer document for a new unit, supports the application.
- Record the weight: the trailer weight decides the fee, so have the figure ready before you reach the counter.
- Pay the license fee: trailer license fees follow the state Non-Commercial Trailer License Fee Schedule and depend on the weight and year of the trailer.
- Add the mailing charge: a mailing fee applies when a plate is mailed, and the comparison table lists it.
- Name the plate type: a regular annual plate and a trailer identification plate are not the same order, so say which one you want.
- Keep the county receipt: the receipt is proof of the filing as the title and plate are in process.
What the County Office Needs From You
The clerk works from the paper in front of them rather than from your description of the unit. A complete application carries the owner name that matches your identification, the trailer description and the purchase details the county uses to build the record. A dealer sale usually supplies the ownership side. A private purchase needs a signed title from the seller, and a homemade unit needs whatever ownership evidence you have along with the weight. A blank box sends the form back, so read every field before you join the line at the counter.
Filing at the Counter or Through the Mail
The county treasurer takes the filing in person, and many counties accept the same paper by mail. A mailed filing needs the signed form, the ownership document and a payment the county can process. Send copies rather than the only title you have, and keep the originals until the new title arrives. A plate sent back to you adds a mailing charge, and the county will not release it until the order clears. Ask the clerk which address the county uses for trailer mail before you seal the envelope.
One Plate on a Trailer
A trailer is an exception to the two plate rule that applies to passenger vehicles. One plate goes on the trailer, and that single plate carries the registration for the unit. Nothing mounts on the tow vehicle for the trailer, since the truck or van already carries its own registration. Owners who move from a state that issues a pair sometimes ask for a second plate, and the county has none to give. The rule follows the vehicle class rather than the taste of the owner.
Where the Single Plate Goes
Mount the plate on the rear of the trailer where light reaches it and where a reader can see the number from behind. A plate bolted to a removable ramp or tucked behind a spare tire invites a roadside conversation. Use the bracket the manufacturer provided when there is one, and check the fasteners after the first long haul. A trailer that flexes will work a loose bolt free, so a quick check before each trip is worth the minute it takes. Carry a spare bolt in the toolbox.
Why Trailers Sit Outside the Two Plate Rule
The two plate requirement exists so a vehicle can be read from either end. A trailer is never the leading vehicle in a combination, so the state asks for one plate and places it at the back of the unit. That logic keeps the cost down, since one piece of metal covers the whole trailer. The exception sits in the same rule that covers motorcycles and recreational vehicles, and a county clerk applies it without any special request from the owner.
The Annual Trailer Plate
The regular annual trailer plate is the default for a light trailer. It renews each year, and the fee follows the state schedule rather than a flat rate. A trailer used with an automobile, a pickup or a van that weighs less than 6,000 pounds must carry this plate, and there is no restriction on the weight the trailer carries. That last point surprises owners who expect a light tow vehicle to cap the load. The trailer plate does not carry such a cap.
- Default for light tow vehicles: a trailer used with an automobile, pickup or van under 6,000 pounds carries the annual trailer plate.
- No load ceiling: the annual plate carries no restriction on the weight the trailer hauls.
- Fee from the schedule: trailer license fees follow the state Non-Commercial Trailer License Fee Schedule.
- Weight and year matter: the charge depends on the weight and the model year of the trailer.
- Mailing costs extra: a mailing fee applies when the plate is mailed.
- Repeats each year: the annual plate is a recurring charge rather than a one time purchase.
The Fee Schedule Behind the Annual Plate
The Non-Commercial Trailer License Fee Schedule sets the charge, and two variables drive it. One is the weight of the trailer. The other is the model year. A heavier unit and a newer year both move the figure up, so two trailers of the same length can land on different lines of the schedule. The county treasurer reads the schedule against your own record. A quote from a neighbor with a different trailer is a rough page at best, and the county figure is the one that matters.
Trailers Under 6,000 Pounds
The 6,000 pound figure belongs to the tow vehicle, not to the trailer. A half ton pickup or a family van under that line pulls a trailer on the annual plate, and the trailer may carry any load the combination can handle safely. Owners often read the number the other way around and assume it caps the trailer. The statute ties the plate type to the vehicle doing the pulling, so weigh or look up the truck before you choose a plate.
The Trailer Identification Plate
A trailer pulled by a truck licensed under the declared gross weight schedule, or by a commercial licensed vehicle, may display a trailer identification plate instead of the annual plate. The identification plate carries a one-time charge as the same owner keeps the trailer, and it is the only plate required on that trailer. For an owner who keeps a heavy trailer for years, the saving shows up after the first season and keeps growing. The plate stays with the trailer and with the owner who bought it.
The One Time Charge
The identification plate is bought once, and the charge does not return as the same owner holds the trailer. That is the whole cost of the plate itself, apart from the mailing charge when the county sends it to you. Compare that with an annual plate that returns every year on the schedule. The break even point arrives quickly for a trailer that stays in one family. A change of owner restarts the arrangement and the next owner pays again.
When the Identification Plate Fits
The plate fits a trailer behind a truck that is licensed under the declared gross weight schedule. It fits a trailer behind any commercial licensed vehicle. What it does not fit is a trailer behind a light pickup or van under 6,000 pounds, since that combination takes the annual plate. No identification plate may be displayed on a recreational vehicle. Read the truck registration before you order, since the plate type follows the towing vehicle rather than the trailer.
Homemade Trailers and Assigned Numbers
A trailer built in a garage or assembled from a kit has no manufacturer document, so the state uses an assigned number to give it an identity. The route splits on weight. A unit over 3,000 pounds goes through an assigned VIN and an inspection. A unit of 3,000 pounds or less may request an assigned serial number from the county treasurer to start the title application. The weight of the finished trailer decides which door you use.
Trailers Over 3,000 Pounds
A homemade trailer above 3,000 pounds needs an assigned VIN and an inspection before the title can move forward. The inspection confirms the unit is what the application says it is, and the assigned number gives the state a record to attach the title to. Build the file before you start, with any receipts for steel, axles, lights and tires. A clerk who can see the parts trail has an easier time with the application. Plan for the inspection to add time to the process.
Trailers of 3,000 Pounds or Less
A lighter homemade trailer may request an assigned serial number from the county treasurer, and that number starts the title application. The request goes in at the counter where you live. Once the number is attached to the record, the rest of the filing follows the normal path with Form 1001. Keep the assigned number someplace safe, since it becomes the identifier for the trailer on every later document and on the plate order itself.
Which Plate You Need
A light trailer and a heavy trailer can look alike, so the plate choice depends on the truck in front. The table below sets the two plate types side by side.
| Item | Annual trailer plate | Trailer identification plate |
|---|---|---|
| Tow vehicle | Automobile, pickup or van under 6,000 pounds | Truck on the declared gross weight schedule, or a commercial licensed vehicle |
| Charge | State Non-Commercial Trailer License Fee Schedule | $10 |
| Repeat cost | Each year | One time as the same owner keeps the trailer |
| Load limit | No restriction on weight carried | Not set by the trailer plate |
| Plate count | One plate | One plate, and the only plate required on that trailer |
| Mailing | $12 when the plate is mailed | $12 when the plate is mailed |
Reading the Table Against Your Truck
Start with the registration for the vehicle that pulls the trailer. If that truck sits on the declared gross weight schedule, the identification plate is open to you. If the truck is a pickup or van under 6,000 pounds, the annual plate is the answer. A commercial licensed vehicle opens the identification plate as well. Write the truck figure on the same sheet as the trailer weight, since the two numbers answer different questions at the counter.
Towing Rules and Gross Weight
Gross weight ties the truck, the trailer and the load together, and the declared figure appears on the truck registration rather than on the trailer plate. The plate rule asks what kind of truck does the pulling. The towing question asks whether the combination stays within the weight the truck is licensed to move. Those are separate checks, and passing one does not settle the other. Both belong in the same conversation at the county counter before you order a plate.
What Gross Weight Covers
The declared gross weight on a truck registration is the total the vehicle is licensed to move, and a trailer and its load add to that total. A truck licensed at a low figure can still pull a trailer on the annual plate, since the plate rule and the declared weight schedule are not the same test. What the declared figure controls is how much weight the combination may put on the road. Read the truck registration before you load the trailer for a trip.
Checks Before You Leave the Yard
A short checklist covers most of the trouble an owner meets on the first trip with a new trailer.
- Truck registration class: confirm whether the truck sits on the declared gross weight schedule or is a light pickup or van.
- Trailer weight: know the trailer weight before you choose a plate type.
- Plate on the rear: the single plate belongs at the back of the trailer where it can be read.
- Fasteners: check the bracket and bolts after the first trip and before each long haul.
- Owner name: keep the title and the registration in the name that matches your identification.
- Receipts: hold on to the county receipt and the mailing record until the plate is mounted.
Replacing a Lost Trailer Plate
A missing trailer plate needs an order rather than a repair, and the paper depends on which plate you held. An identification plate has its own duplicate route with an affidavit. An annual plate follows the replacement path the county uses for a registration plate. In both cases the county treasurer of your residence takes the filing, and a mailed plate adds a mailing charge. Report the loss quickly, since an unplated trailer on the road invites a stop.
The Duplicate Plate Affidavit
A duplicate identification plate needs a duplicate plate affidavit and the same fixed charge as the original. The affidavit is the state record that the original is gone, so fill it in completely and sign it at the counter. The fee matches the original charge for the plate. Bring your identification and the trailer details so the clerk can match the affidavit to the right record. Keep a copy of the affidavit with the trailer file for later reference.
A Lost Annual Plate
An annual plate replacement runs through the county office that issued the original. Bring the registration card and your identification, and expect the mailing charge if the new plate is sent to you. The county can read the record and confirm what the replacement costs on your trailer. A plate lost on the highway may turn up later, so keep the new one mounted and the old paperwork filed. Do not run the trailer without a plate in the meantime.
Frequently Asked Questions
These are the trailer questions that come up most often at a South Dakota county counter. Each answer states the general rule, and the county treasurer confirms the details on your own record.
Do I need two plates on a South Dakota trailer?
No. A trailer is an exception to the two plate rule and displays one plate. Mount it at the rear of the trailer where light reaches it and where a reader can see the number. The tow vehicle carries its own registration, so nothing extra goes on the truck for the trailer. One plate covers the unit for the whole registration year.
How much does a South Dakota trailer plate cost?
Trailer license fees follow the state Non-Commercial Trailer License Fee Schedule and depend on the weight and year of the trailer, so there is no single figure. A trailer identification plate carries a one-time charge as the same owner keeps the trailer. A mailing charge applies when a plate is mailed, and the comparison table above lists both amounts.
What is a trailer identification plate?
A trailer identification plate is an alternative to the annual trailer plate. A trailer pulled by a truck licensed under the declared gross weight schedule, or by a commercial licensed vehicle, may display one. It carries a one-time charge as the same owner keeps the trailer, and it is the only plate required on that trailer.
How do I title a homemade trailer in South Dakota?
A homemade trailer over 3,000 pounds must go through an assigned VIN and an inspection. A trailer of 3,000 pounds or less may request an assigned serial number from the county treasurer to start the title application. Either way the title work uses Form 1001 and is filed in the county of your residence.
Can a recreational vehicle carry a trailer identification plate?
No. No identification plate may be displayed on a recreational vehicle. The plate belongs to a trailer pulled by a truck on the declared gross weight schedule or by a commercial licensed vehicle. A recreational vehicle follows its own registration rules, and the trailer plate does not transfer to it.