CO₂ toll classes: why similar trucks can have different toll costs

Two similar trucks can meet the same Euro VI standard and have a similar configuration, yet still be subject to different toll rates. One reason may be their CO₂ emission class, which operates alongside the Euro class in road toll systems.

The Euro class primarily relates to air pollutant emissions, while the CO₂ class is based on vehicle efficiency determined under EU rules for heavy-duty vehicles.

The issue became particularly relevant on 1 July 2026 for vehicles with a technically permissible maximum laden mass above 16 tonnes. Updated reference values for vehicle groups and subgroups 4, 5, 9 and 10 lowered the thresholds used for classification. Toll Collect indicated that a truck assigned to class 3 in 2025 could move to class 2 or 1 following the change, resulting in a higher toll cost.

Five classes and three different approaches

EU rules provide for five CO₂ emission classes:

• class 1 covers vehicles that do not meet the conditions for a higher class or lack the data required to confirm one,
• class 2 requires a result more than 5% below the applicable emission reduction trajectory,
• class 3 requires a result more than 8% below that trajectory,
• class 4 covers low-emission heavy-duty vehicles,
• class 5 covers zero-emission vehicles under the relevant definitions.

Classes 2 and 3 are relative. A vehicle is not compared with the entire market, but with the value applicable to its subgroup and reference period.

Classes 4 and 5 are based on separate criteria for low- and zero-emission vehicles. Class 1 serves as the baseline and also includes vehicles for which compliance with the requirements of a more favourable class cannot be confirmed.

Why the first registration date changes the result

Reference values follow a declining trajectory. ASFINAG states that the reduction was 2.5% per year until 2025 and is 3% per year from 2026 to 2030. The reference period changes on 1 July.

As a result, technically identical vehicles first registered on 30 June and 1 July can receive different classes.

The date also matters in the opposite direction. Vehicles first registered before 1 July 2019 are generally assigned to class 1 because the required reference values are not available for them. An exception may apply to vehicles meeting the relevant zero-emission criteria.

A recent model year does not guarantee a more favourable class either. Specific emissions data and correct assignment to the appropriate vehicle subgroup are also required.

The VECTO subgroup matters more than the model name

Classification uses the result determined through VECTO and the vehicle subgroup.

Group 4, for example, includes UD, RD and LH profiles, corresponding to urban delivery, regional delivery and long haul. The subgroup depends on the vehicle's technical configuration and the mission profile defined by the regulations, rather than its commercial model name.

This can explain seemingly minor differences that lead to different classification results. A cab with a sleeper berth, for example, can affect assignment to a long-haul profile, which has a different reference value from a regional profile.

Comparing only the g CO₂/tkm values of two vehicles belonging to different subgroups can therefore lead to incorrect conclusions.

What changed on 1 July 2026?

Commission Implementing Regulation (EU) 2025/2545 updated the baseline values.

For subgroup 4-LH, the value indicated by Toll Collect fell from 105.96 to 103.32 g CO₂/tkm, while for 5-LH it fell from 56.00 to 55.02 g CO₂/tkm. Since the thresholds for classes 2 and 3 are calculated against the reduction trajectory, a lower baseline can make it more difficult to retain a more favourable class.

This does not mean that every vehicle automatically changed class on 1 July. The result depends, among other factors, on the first registration date, vehicle subgroup and specific CO₂ emissions.

The change does, however, show that a classification stored in a toll system cannot always be treated as a permanent vehicle attribute.

The six-year reassessment that is easy to overlook

Vehicles in classes 2 and 3 are reassessed every six years from the date of first registration. The thresholds in force at the time of reassessment are applied.

As a result, a vehicle may remain in its existing class or be assigned to a less favourable one. Classes 4 and 5 do not follow the same periodic reassessment logic.

The importance of this rule will increase as more vehicles reach their first six-year reassessment date.

Data and documents determine correct classification

Confirming a vehicle's class may require, among other documents:

• the registration certificate showing the first registration date and technically permissible maximum laden mass,
• the Customer Information File, or CIF,
• the Certificate of Conformity, or CoC, if the required data are not clearly available from the other documents,
• in some cases, an individual approval document.

Toll Collect states that specific CO₂ emissions can be found, among other places, in fields 2.3 or 2.6.1 of the CIF, field 49.5 of the CoC or field V.7 of the vehicle registration certificate.

In the German system, vehicles are initially assigned to class 1. To obtain a more favourable class, the user must provide the relevant data and documents needed to confirm it.

In Austria, CO₂ classes 2-5 also require evidence. ASFINAG allows 30 days from declaring or changing a tariff characteristic to provide the required documentation.

If the required data are not properly confirmed, the vehicle may be assigned to CO₂ class 1. In practice, a documentation issue can therefore directly affect the cost of a journey.

How much can a class change cost in Germany?

The difference between classes may not look significant when calculated per kilometre. Over a high annual mileage, however, it becomes noticeable.

For a vehicle combination with a technically permissible maximum laden mass above 18 tonnes and at least five axles, the CO₂ component of the German toll is currently:

• EUR 0.158/km in class 1 for Euro VI,
• EUR 0.150/km in class 2,
• EUR 0.142/km in class 3.

The difference between classes 3 and 1 is therefore EUR 0.016/km, or EUR 16 per 1,000 km of tolled road.

At 120,000 km per year in Germany, this would amount to a difference of EUR 1,920 per vehicle, assuming unchanged rates and that the entire distance is subject to the same tariff.

This example covers only the CO₂ component of the German toll, not the total toll rate. The total charge also includes components related to infrastructure, air pollution and noise.

It does, however, show why correct CO₂ classification can have a measurable impact on transport cost calculations.

What should be checked when calculating transport costs?

When calculating the cost of a journey, knowing the vehicle's Euro standard alone may no longer be enough. Its CO₂ class and whether that class has been correctly confirmed in the relevant toll system may also matter.

Particularly on routes through Germany and Austria, it is worth checking:

• the CO₂ class assigned to the vehicle in the relevant toll system,
• the first registration date,
• the vehicle subgroup and specific CO₂ emissions,
• the availability of data and documents required to confirm the class,
• the reassessment date for vehicles in classes 2 and 3.

A common EU framework for classification does not mean identical procedures in every country. Evidence requirements, deadlines and toll rates should therefore be checked in the relevant national toll system.

The same Euro standard does not mean the same toll rate

CO₂ classes mean that assessing the cost of a truck journey is no longer just a matter of checking the Euro standard, vehicle weight or number of axles.

Specific CO₂ emissions, the vehicle subgroup, first registration date and correct confirmation of the data in the toll system also matter.

The change in reference values from 1 July 2026 further shows that a class assigned to a vehicle does not necessarily remain unchanged. Vehicles in classes 2 and 3 are also subject to reassessment every six years.

When planning international transport costs, it is therefore worth checking not only the route and current toll rates, but also which CO₂ class is actually assigned to the vehicle in the relevant toll system.

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This article is for informational purposes only. Vehicle classification, documentation requirements and road toll rates may change, so the current rules of the relevant toll system should be checked before calculating the cost of a journey.