Quick Summary:
- Leave the switch as found unless your rental agreement instructs otherwise.
- ON usually means tolls bill to the car, then your rental.
- Do not use your own transponder and the car’s transponder together.
- On cashless roads, turning it OFF may still trigger plate-bill charges.
In Florida, toll roads are everywhere, and many are now cashless. That is why lots of rental cars come with a SunPass transponder fitted, or with toll-by-plate enabled. Then you notice a small ON/OFF switch and wonder whether you should touch it at all. The short, practical answer is this: treat the switch as part of the rental’s toll set-up, not as a universal “avoid tolls” button.
This guide explains what that in-car switch usually controls, when to leave it alone, and how to avoid the two outcomes that frustrate travellers most, double-billing and violations or admin fees on cashless toll roads.
What the SunPass switch actually controls
That ON/OFF switch is usually connected to the vehicle’s toll device mode, not the road network. Florida toll gantries decide whether you have paid based on what they detect as you pass. The switch typically controls whether the transponder in the car actively broadcasts its ID to the toll reader.
When set to ON, the transponder is more likely to be read, and tolls are posted to the account linked to that transponder, which for a rental car is typically handled by the rental company’s toll programme. When set to OFF, the transponder may be muted, but you are not magically “toll-free”. On many Florida roads, if the transponder is not detected, the system falls back to reading the number plate. That charge then goes through the rental company via toll-by-plate, often with additional admin or processing fees depending on the provider and your agreement.
Because each rental company and toll programme is slightly different, the switch can be labelled in different ways. Some vehicles have a simple ON/OFF, others have a sliding cover, and some have no switch at all. What matters is the billing path it triggers in your contract.
When you should leave the switch alone
Most of the time, the safest option is to leave the switch exactly as you found it at pick-up. The vehicle may have been prepared to work with the rental company’s toll system, and changing the setting mid-trip can create messy billing, especially if you enter and exit tolled segments in different modes.
This is particularly relevant if you are picking up at a busy hub where the toll network is hard to avoid. For example, visitors arriving through Orlando International Airport (MCO) car rental will often find that the simplest routes to resorts and theme parks include tolled expressways. If you do not know the exact toll rules for your rental, leaving the setting alone reduces the chance of accidental non-payment.
Also leave it alone if your paperwork says tolls are handled automatically, you accepted an optional toll product, or the vehicle has signage indicating the device must remain enabled. In those cases, switching it off can push your charges into toll-by-plate, which rarely saves money once admin fees and delayed billing are included.
When switching OFF can be appropriate
There are limited situations where switching OFF may make sense, but only if you are sure how your rental is set up.
If your rental agreement clearly states that transponder toll charges apply only when the unit is ON, and you intend to avoid toll roads entirely, switching it OFF can help prevent accidental transponder reads. This is still not a guarantee on cashless roads if plate billing is active, but it can stop transponder-based charges where the alternative is a different billing method.
Switching OFF can also be useful if the rental company has instructed you to do so in specific circumstances, for example if the unit is malfunctioning and they have told you to rely on a different method. If that happens, document it, note the time and the person you spoke to, and keep any written confirmation.
Avoiding double-billing: the big rule for Florida car hire
Double-billing almost always happens when two toll payment methods are competing. The most common causes are:
1) Using your own SunPass or E-ZPass while the car’s unit is ON. If your personal transponder is in the car and readable, the gantry might charge your account, while the rental transponder also triggers a charge, or the rental’s plate billing triggers later. Even if only one charge posts, disputes become harder because you have mixed accounts in the same vehicle.
2) Mixing modes during the same trip. If you switch ON for one toll road, then OFF for another, you can end up with some tolls billed to the transponder programme and others billed by plate. That looks like duplication when charges arrive on different dates with different descriptions.
3) Paying cash on roads that still have cash lanes, while a transponder is active. This is less common now, but a few facilities may still offer staffed lanes at certain times. If you accidentally use a toll lane that reads the transponder and then hand over cash, you could be charged twice. On modern Florida toll plazas, lane signage matters, so slow down early and choose the correct lane for your payment method.
The practical approach is to pick one method for the entire rental period. For most visitors, that is the rental’s toll programme, because it is designed to match the vehicle’s equipment and number plate billing.
Cashless toll roads: why OFF does not mean “no charge”
Florida has many cashless toll points where there is no opportunity to pay on the spot. The system reads a transponder or captures a number plate image. That is why turning the switch OFF can still result in a toll charge, just routed differently.
If the transponder is OFF and the plate is billed, you might receive charges later through the rental company, sometimes bundled, sometimes itemised. This can be surprising because drivers assume “OFF” equals “I opted out”. In reality, you opted out of that transponder’s broadcast, not the obligation to pay the toll.
Cashless tolling is common around major visitor routes, including Orlando area expressways. If you are heading towards theme parks and staying near Disney, routes can include toll sections even when you are just following navigation suggestions. Travellers using car hire for Disney area Orlando should plan on tolls being part of normal driving unless they deliberately choose toll-free alternatives.
How to decide what to do at pick-up
Before you drive away, take two minutes to get clarity. You do not need to become a toll expert, you just need consistent rules for your trip.
Step 1: Check your contract for toll terms. Look for wording about a toll programme, transponder charges, toll-by-plate, daily fees, and administrative fees. If the contract says tolls will be billed automatically, assume the transponder setting is part of that.
Step 2: Inspect the car for toll instructions. Many rentals include a small card or sticker explaining whether the unit should remain ON. If the vehicle is an SUV or a larger family vehicle, it is still the same toll logic. For instance, if you arranged SUV rental in Fort Lauderdale (FLL), check the windscreen area and centre console for any toll device notes before adjusting anything.
Step 3: Decide your payment method for the whole rental. Either rely on the rental company’s toll system, or use your own transponder only if the rental company explicitly allows it and you can ensure the car’s device will not be read. In practice, “use your own” is often more hassle than it is worth for short trips.
Step 4: If you choose the rental system, keep the switch consistent. Consistency is what prevents mixed billing streams. If the car is set to ON at pick-up and you are comfortable with the rental’s toll policy, leave it ON throughout.
Navigation tips to reduce toll surprises
Toll charges are not inherently bad, but unexpected tolls are. A few settings can keep things predictable:
Use your map app’s “avoid tolls” option if you truly want toll-free routes. Be aware this can add time and fuel, especially in metro areas.
Do not blindly accept “fastest route” suggestions. In Florida, “fastest” often means tolled expressways.
Plan airport and city transfers with tolls in mind. If you are travelling on the Gulf Coast around Tampa, for example with car hire in Tampa (TPA), you may encounter toll bridges or express lanes depending on your destination. Decide upfront whether you prefer speed or savings.
What to do if you think you were billed twice
If charges look duplicated, start by separating “toll amount” from “service fee”. A single toll event can appear as a toll charge plus an admin or processing fee. That is not duplication, but it can look like it.
If you genuinely see two toll charges for the same location and time, gather evidence before disputing:
Take screenshots of your toll timeline if you used a personal transponder account. Keep your rental agreement and receipt. Note the date, approximate time, and facility name if shown. Then contact the rental provider with that detail and ask them to trace the transaction IDs. Disputes go faster when you provide a narrow window rather than a general complaint.
Preventing violations and admin fees
Toll violations in a rental context usually stem from unpaid toll-by-plate invoices, delays in matching the plate to the rental agreement, or driving through toll facilities without an accepted payment method. To reduce risk:
Use the toll method your contract expects. Keep the switch in a consistent position. Avoid switching it on and off “to test it”. If you are unsure, assume a cashless road will bill by plate and that the rental company will pass the charge to you.
If you believe the transponder is not being read and you are worried about violations, do not try to fix it while driving. Pull over safely, check whether the unit is properly mounted, and call the rental provider for guidance. Your goal is not to avoid tolls at any cost, it is to avoid unpaid tolls that trigger added fees.
Bottom line for Florida car hire and SunPass switches
The ON/OFF switch is best thought of as a billing pathway selector, not a toll shield. ON usually routes tolls through the rental programme’s transponder process. OFF can still result in tolls via plate billing, especially on cashless roads, and may not save you money once fees are considered.
To keep your trip smooth, choose one toll approach for the entire rental, avoid mixing your own transponder with the car’s device, and only change the switch if your rental documentation clearly tells you to.
FAQ
Q: Does turning the SunPass switch OFF mean I will not pay tolls?
A: No. On many Florida cashless toll roads, the system can bill by number plate if no transponder is read, and the rental company may pass that charge to you with fees.
Q: Can I use my own SunPass in a rental car?
A: Sometimes, but it is risky unless the rental company confirms how to prevent the in-car transponder or plate billing from also charging. Mixing methods is the main cause of double-billing.
Q: I left the switch ON and avoided toll roads, will I still be charged?
A: You are only charged if you pass toll points or toll-by-plate cameras. If you truly did not use tolled facilities, there should be no toll charges, though fees may apply only if tolls occurred.
Q: Why did my toll charges appear days after my trip?
A: Toll-by-plate and rental toll programmes often post later because invoices must be matched to the vehicle and rental period before being forwarded to you.
Q: What should I do if I think a toll charge is wrong?
A: Collect the date, time, location, and any account screenshots, then contact the rental provider to trace the transaction. Clear details help them confirm whether it is a toll plus a fee, or a true duplicate.
