Colorado toll roads and how payment works

Colorado has three toll roads operated by the Colorado Department of Transportation (CDOT): I-25 between Castle Rock and the New Mexico border, US 36 between Boulder and I-25, and I-270 between I-25 and I-76. You can pay tolls three ways: with a transponder (a small device mounted on your windshield), by license plate (CDOT photographs your plate and bills you), or with a one-time toll pass if you're visiting.

Most Colorado drivers use a transponder because it offers the lowest toll rates and the easiest tracking. If you don't have one, CDOT will photograph your license plate as you pass through a toll point and send you an invoice by mail. This method costs more per trip than a transponder but works if you only drive tolls occasionally.

Tolls vary by time of day and traffic conditions on I-25 and US 36 — they're higher during rush hour and lower at night. I-270 has a flat rate. You can check current toll rates on the CDOT website before you drive.

Key Takeaways

  • Colorado operates three toll roads: I-25 south of Denver, US 36 between Boulder and I-25, and I-270 between I-25 and I-76.
  • A transponder gives you the lowest toll rates and automatic payment, while license plate billing costs more but requires no equipment.
  • Tolls on I-25 and US 36 change throughout the day based on traffic; I-270 charges a fixed rate.
  • If you don't pay a toll invoice within 30 days, CDOT adds a penalty and can suspend your vehicle registration.
  • Visitors can buy a one-time toll pass online or at certain locations before driving.

Getting a transponder and setting up an account

To get a transponder, you create an account on the CDOT toll website (expresstoll.com) and order one online. The transponder itself is free, but you must prepay a balance into your account — the minimum is usually $25 to $40, depending on the current promotion. You load money into your account, and tolls are deducted automatically as you drive.

The transponder arrives by mail in about 5 to 10 business days. Once it arrives, you mount it on your windshield (usually behind the rearview mirror), set up it in your online account, and you're ready to use the toll roads. Your account shows your trip history and remaining balance, and you can set up automatic reloads so your balance never runs out.

If you lose or damage your transponder, you can order a replacement through your account. There is usually a small fee for a replacement device.

Paying tolls by license plate if you don't have a transponder

If you drive through a toll point without a transponder, CDOT's cameras photograph your license plate. Within 10 to 14 days, you'll receive an invoice by mail at the address registered with your vehicle's title. The invoice shows the toll amount, which is higher than the transponder rate, plus a processing fee.

You can pay the invoice online, by phone, or by mail. Payment is due within 30 days of the invoice date. If you pay late, CDOT adds a penalty fee and can report the debt to a collection agency. If the debt remains unpaid, CDOT can place a hold on your vehicle registration renewal, which means you won't be able to renew your registration until the toll debt is paid.

If you drive the toll roads regularly without a transponder, the per-trip cost will be significantly higher than getting a transponder. Most drivers who use tolls more than a few times per year save money by switching to a transponder account.

One-time toll passes for visitors

If you're visiting Colorado and need to drive a toll road, you can buy a one-time toll pass online through the CDOT website. The pass covers a single trip on one of the three toll roads and is valid for 24 hours from the time you purchase it. You receive a confirmation number by email, and you enter that number into a kiosk at the toll point, or you can display it on your phone.

One-time passes cost more than a transponder trip but less than a license plate invoice. This option is useful if you're renting a car or only passing through Colorado once.

What happens if you don't pay a toll invoice

If you receive a toll invoice and don't pay within 30 days, CDOT sends a second notice with a penalty fee added. If you still don't pay, CDOT can place a hold on your vehicle registration renewal. This means you cannot renew your registration online or at the DMV until the toll debt, penalties, and any collection fees are paid in full.

The hold remains in place even if you sell the vehicle — the debt follows the license plate, not the owner. If you believe you received an invoice in error (for example, you had a transponder and it malfunctioned), you can dispute it by contacting CDOT toll customer service with documentation.

If you're having trouble paying a toll invoice, contact CDOT to discuss payment options. They may be able to work out a payment plan in some cases, though this is not may provide.

Managing your transponder account and checking your balance

Once you have a transponder account, you can log in to expresstoll.com anytime to check your balance, view your trip history, update your payment method, and change your account settings. You can see exactly which tolls you've paid and when you drove them.

Most accounts allow you to set up automatic reloads, which means your account is topped up automatically when your balance drops below a certain amount. This prevents your balance from running out while you're driving. You can change the reload amount and the threshold that triggers a reload in your account settings.

If you move or change your vehicle, update your account information so invoices and notices reach you. If you sell your vehicle, you can transfer your transponder to a new vehicle or request a refund of your remaining balance.

Tolls and your vehicle registration

Unpaid toll debt is directly linked to your vehicle registration status in Colorado. When you renew your registration, the DMV checks whether there are any outstanding toll debts on your license plate. If there are, your registration renewal will be blocked until the debt is paid.

This applies whether you owe tolls from license plate invoices or from a transponder account that went unpaid. The hold is automatic and affects your ability to legally drive the vehicle. If you're unsure whether you have outstanding toll debt, you can contact CDOT toll customer service or check your account online if you have a transponder.

Frequently Asked Questions

Can I use the same transponder in multiple vehicles?

No. Each transponder is linked to one vehicle and one account. If you drive multiple vehicles, you need a separate transponder for each one, though they can all be linked to the same account for billing purposes. You can transfer a transponder to a different vehicle by updating your account online.

What if I'm charged a toll but I had a transponder?

Contact CDOT toll customer service with your transponder number and the date of the trip. If your transponder malfunctioned or wasn't read properly, CDOT can investigate and may reverse the charge. Keep your transponder clean and make sure it's properly mounted so it reads correctly every time.

Do I have to pay tolls if I'm just passing through Colorado?

Only if you drive on one of the three toll roads (I-25 south of Denver, US 36, or I-270). If you take non-toll routes, you won't be charged. You can check the CDOT website for toll-free alternate routes before you drive.

Can a toll hold prevent me from getting a new license plate?

A toll hold blocks registration renewal, which means you can't legally renew your plates. However, it doesn't prevent you from getting a new license plate for a different vehicle. The hold is specific to the license plate with the outstanding toll debt.

How long does it take to get a refund if I close my transponder account?

Refunds of your remaining balance typically take 7 to 10 business days after you close your account. You can request a refund through your online account or by contacting CDOT toll customer service.