CO2 emissions class on the German toll: why the default is the most expensive

Since December 2023, the German truck toll has consisted of four components: infrastructure, air pollution, noise, and CO2 emissions. The first three depend on weight, axle count, and Euro standard — figures the owner has little control over. The fourth depends on the CO2 emissions class, and it's the one most often set incorrectly.

Five classes and one default

Every chargeable vehicle is assigned to one of five CO2 emissions classes. The first is the most expensive and applies to older vehicles. The second and third are reachable by efficient new diesel engines. The fourth is for low-emission drivetrains, the fifth for zero-emission vehicles.

The difference isn't symbolic. A five-axle, over-18-tonne Euro VI tractor unit pays 34.8 ct per chargeable kilometre in class 1. In class 2 it's 34.0, in class 3 it's 33.2, in class 4 it's 26.9 ct/km.

And here's the crucial detail many fleets learn too late: without submitted proof of conformity, a vehicle is automatically billed at the first, most expensive class. The operator never upgrades it to a better class on its own initiative. Reclassification only happens once the owner submits documents themselves.

Who can be reclassified

The right to request a better class has one boundary: the vehicle must have been first registered since 1 July 2019. Every vehicle registered before that automatically stays in class 1, and there's nothing to be done about it.

Acceptable proof includes the registration certificate, the certificate of conformity (CoC), manufacturer CIF data, or an individual approval sheet. For vehicles registered in Germany, the Euro standard is stated in Part I of the registration certificate, so classification is simpler. For vehicles registered outside Germany, proof has to be submitted separately — this affects nearly every Baltic and Polish carrier.

An additional wrinkle: the classification thresholds were tightened on 1 July 2026. That means a class determined before that date doesn't necessarily match the current thresholds, and the assessment has to follow whichever version was in effect at the time.

What this means in money

A five-axle tractor unit covering 80,000 chargeable kilometres a year pays about €27,840 at CO2 class 1. Reclassified to class 3, the same mileage costs about €26,560 — a difference of around €1,280 a year. Reclassified to class 2, the difference is about €640.

For a fleet of thirty tractor units where twelve vehicles qualify for class 2 or 3, that's €7,680–15,360 a year.

This is an illustrative calculation based on publicly published rates, not confirmed statistics. Your actual result depends on your fleet composition, kilometres driven in Germany, and each vehicle's registration date.

Two different outcomes

The wrong class costs money in two directions. Backward — as an overpayment that can be recovered within a three-year window. Forward — as a higher rate that repeats every month the vehicle stays in service.

The second is usually larger. A one-time refund for past years is a defined amount; reclassification keeps paying off for as long as the tractor unit works.

What this article doesn't tell you

It doesn't tell you whether your specific vehicle qualifies for a better class — that depends on the engine data in the certificate of conformity and on the thresholds in effect at the time. Without CoC or CIF data it can't be assessed, and there's no room to guess here.

It also doesn't tell you how many errors are in your own invoices. Every fleet is different.