Colorado tollway payment options and how they work

Colorado has three tollways that charge per use: 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 account (the cheapest option), by license plate invoice (you receive a bill by mail), or through Pay-by-Plate (a one-time online payment). Most drivers use a transponder because the per-mile rate is lower than the other methods.

The Colorado Department of Transportation (CDOT) operates these roads through a program called ExpressToll. When you drive a tollway, sensors read either your transponder or your license plate. If you have an active transponder account, the toll is deducted automatically. If you don't, CDOT photographs your plate and sends you an invoice. You then have a window to pay online or set up an account before late fees explore.

Key Takeaways

  • Transponder accounts charge the lowest per-mile rate and deduct tolls automatically; you load money into the account in advance or set it to auto-replenish.
  • If you don't have a transponder, CDOT sends a bill to the address on your vehicle registration within 10 days of driving the tollway.
  • Paying by invoice costs more per mile than a transponder but requires no upfront account setup.
  • Late fees and collection actions begin if you ignore invoices; unpaid tolls can affect your vehicle registration renewal.
  • You can dispute a toll charge if you believe it was issued in error, but you must contact CDOT within 30 days of the invoice date.

Setting up and funding an ExpressToll transponder account

To open a transponder account, visit the ExpressToll website (expresstoll.com) or call 877-MY-EXPRS (877-693-9777). You will need your vehicle's license plate number, vehicle identification number (VIN), and a valid email address. The transponder device itself is free, and CDOT mails it to you within 5 to 7 business days.

Once you receive the transponder, mount it on your windshield and set up it online. You then fund the account by adding money upfront—the minimum is typically $25—or by setting up automatic replenishment. With auto-replenishment, the account charges your payment method (credit card, debit card, or bank account) when your balance drops below a threshold you choose. This prevents your account from running empty and triggering invoice billing.

The transponder rate varies by time of day and congestion level. During peak hours, tolls are higher; during off-peak times, they are lower. CDOT publishes rates on its website, but the exact charge depends on the distance traveled and the time you drive. Transponder users pay roughly 30 to 50 percent less per mile than drivers who receive invoices.

License plate invoicing and Pay-by-Plate

If you drive a tollway without a transponder, CDOT captures your license plate with a camera. Within 10 days, you receive an invoice by mail to the address registered with your state vehicle registration. The invoice shows the date, time, location, and toll amount. You have 30 days from the invoice date to pay online at expresstoll.com, by phone, or by mail.

Paying by invoice costs more than using a transponder. A single toll on I-25 or US 36 can range from $1 to $8 or more depending on congestion and distance, whereas a transponder user on the same route might pay $0.50 to $5. If you drive the same tollway regularly, a transponder saves money quickly.

Pay-by-Plate is a one-time payment option for occasional users. Instead of waiting for an invoice, you can visit expresstoll.com within 24 hours of driving the tollway, enter your license plate and the date of travel, and pay when ready. This option costs the same as invoice billing but lets you settle the charge before the bill arrives in the mail.

What happens if you don't pay a toll

If you ignore an invoice, CDOT adds a late fee—typically $25 per unpaid toll—after 30 days. If you still don't pay after 60 days, the amount grows and CDOT may refer the debt to a collection agency. Unpaid tolls can also prevent you from renewing your vehicle registration with the Colorado Department of Revenue.

CDOT can place a hold on your registration renewal until the toll debt is resolved. This means you cannot legally drive the vehicle or renew your license plates. The hold remains in place even if you move out of state, because it is tied to your vehicle's VIN and title.

If you believe a toll was issued in error—for example, you were not driving that vehicle or the charge is a duplicate—you can dispute it. Contact CDOT within 30 days of the invoice date with your explanation and any supporting documents. CDOT will review the dispute and either remove the charge or explain why it stands.

Transponder account management and troubleshooting

Once your transponder account is active, you can manage it online through the ExpressToll portal. Log in to view your balance, transaction history, and current toll rates. You can also update your payment method, change your auto-replenishment settings, or add multiple vehicles to a single account.

If your transponder stops working—for example, if the battery dies or the device is damaged—contact ExpressToll to request a replacement. CDOT will mail a new device at no charge. Until the new one arrives, your vehicle will be billed by license plate invoice, so monitor your mail for bills.

If you sell your vehicle or no longer drive Colorado tollways, you can close your account online or by phone. Any remaining balance will be refunded to your payment method within 7 to 10 business days. If you transfer the vehicle to another driver in your household, you can update the account to reflect the new primary driver.

Transponder accounts for commercial and fleet vehicles

Businesses that operate multiple vehicles can set up a commercial ExpressToll account. This account type allows you to manage tolls for an entire fleet under one billing structure. CDOT issues a transponder for each vehicle, and all charges roll into a single monthly invoice.

Commercial accounts often include volume discounts or negotiated rates, depending on the size of the fleet and usage patterns. To set up a commercial account, contact CDOT directly at 877-MY-EXPRS or visit expresstoll.com and select the business option. You will need to provide your company's tax ID, proof of business registration, and details about the vehicles in your fleet.

Frequently Asked Questions

Can I use the same transponder in multiple vehicles?

No. Each transponder is linked to one vehicle's license plate. If you own multiple vehicles, you need a separate transponder for each one. You can manage all transponders under a single account and fund them from one payment method, but each device must be mounted in its assigned vehicle.

What if I drive a rental car on a Colorado tollway?

The rental company's information is on the registration, so CDOT will send the invoice to them. Most rental agencies charge a processing fee (typically $5 to $15) on top of the toll and add it to your final bill. To avoid this fee, ask the rental company if they offer a transponder or if you can pay the toll directly through ExpressToll before returning the car.

Do I have to pay tolls on I-25, US 36, and I-270?

Yes. These are the only tollways in Colorado, and there is no toll-free alternative route on I-25 between Castle Rock and the New Mexico border. US 36 and I-270 have some parallel routes, but they add significant time. If you want to avoid tolls entirely, you must use non-tollway roads.

How long does it take to get a transponder in the mail?

CDOT typically mails transponders within 5 to 7 business days of account creation. If you need one urgently, some customer service centers may have devices available for when ready pickup, though this varies by location. Call 877-MY-EXPRS to ask about same-day or next-day options.

Can I get a refund if I overpaid my ExpressToll account?

Yes. If your account balance is positive when you close it, CDOT refunds the remaining money to your payment method within 7 to 10 business days. You can also request a refund for an overpayment while your account is still active by contacting customer service.