Alcohol interlock as a professional driver: can you keep working?

For anyone who earns a living with a lorry, a bus or a taxi, an alcohol interlock (éthylotest antidémarrage) is much more than an expensive measure. For the entire duration of the measure, you may only drive a vehicle fitted with an alcohol interlock, in principle including your employer’s vehicles. Few employers adapt their fleet for this.

The law does, however, give the judge some room to take your job into account. In this article you will find out how that works, which combinations are impossible and what practical problems you can expect. The basic rules are in our article on the alcohol interlock. The wider framework is set out in our guide to drink driving.

Why is an alcohol interlock so hard on a professional driver?

An alcohol interlock restricts the validity of your driving licence. Code 69 is entered on the licence. From that moment, you may only drive a motor vehicle fitted with an alcohol interlock. The Royal Decree of 26 November 2010 on the supervision programme provides that you must have the device fitted in every motor vehicle you want to drive during that period.

For a private car, that is expensive but feasible. For a driver who takes a different vehicle from the fleet every day, it is often impossible. The alcohol interlock lasts at least one year and cannot be suspended.

Can the judge exclude your lorry or bus?

Yes. Article 37/1, §2 of the Road Traffic Act (loi relative à la police de la circulation routière) allows the judge to exclude one or more vehicle categories from the alcohol interlock. For those categories, your licence then remains valid as normal, without an alcohol interlock. The legislator expressly had in mind drivers who would otherwise lose their job.

Two limits apply:

• Never the category of the offence. If you were driving your car (category B licence), the judge cannot exclude category B, even if you need your B licence for work. The judge can, however, exclude C, C+E, D or D+E.
• Express reasons. The judge must explain in the judgment why the exclusion is necessary.

If you committed the offence with the lorry or bus itself, that category therefore cannot be excluded. An exclusion does not change the stricter alcohol limit for professional drivers either: in your lorry or bus, the limit remains 0.2 per mille.

Which documents help?

• a statement from your employer about your job and the vehicles you drive;
• your employment contract or an extract from it;
• documents showing that it was a one-off incident, such as a clean criminal record or a blood test or hair analysis (see our article on the PEth test, hair analysis and blood values).

Which combinations are impossible?

For professional drivers, a weekend driving ban or a driving ban limited to certain categories is often the best solution. But according to legal writers, the judge cannot combine them with an alcohol interlock. This follows from article 38, §2bis (weekend ban) and article 45 (ban per category) of the Road Traffic Act.

An example: a lorry driver blows more than 1.8 per mille in his car in his free time. A ban for everything except lorries would let him work. But the alcohol interlock is then in principle mandatory, so the judge can only impose that limited ban by giving express reasons for not imposing the alcohol interlock.

If the judge imposes a driving ban (déchéance du droit de conduire) in addition to the alcohol interlock, that ban therefore applies to all categories. The order is fixed: first the ban, then the reinstatement exams (examens de réintégration), and only then the alcohol interlock. For more on these forms of ban, read our article on the weekend driving ban and the ban per category.

Alcohol interlock in a company or lease car

The obligation also applies to your company car. The device can only be fitted by an approved service centre, at your expense. Ask your employer for permission beforehand and, for a lease car, the leasing company as well.

A few more points to watch:

• Colleagues must blow too. Whoever drives the car must use the alcohol interlock. If you have someone else blow in your place, that is a breach of the programme.
• Changing cars. If the device is fitted in another vehicle, it must be checked again. Arrange this in advance with the service centre.
• The certificate. The certificate from the supervising body (organisme d’encadrement) must always be in the car.

What your employer can and must do about fines incurred with a company car is explained in our article on fines with a company car.

Practical problems on the road

The retest within 15 minutes

The alcohol interlock also asks you to blow again during the journey. Under the Royal Decree of 26 November 2010 on the technical specifications, you have 15 minutes to do so. You can therefore first look for a safe place, which can take time with a lorry or bus on the motorway. If you switch off the engine within those 15 minutes, you still have to take the test. A missed test is recorded.

A breakdown

The service centre takes care of maintenance and repairs. If your vehicle is immobilised in Belgium because of a fault in the alcohol interlock, the service centre must assist you. To be approved, it must be able to provide that assistance within 24 hours. Always note the time, the place and what happened, and keep that information for the supervising body.

Journeys abroad

The rules provide no solution for a breakdown abroad. If you drive internationally, discuss this in advance with your employer and your service centre. A lorry stuck abroad can be expensive.

Having the costs deducted from the fine

The alcohol interlock and the supervision programme quickly cost several thousand euros. The judge can reduce the fine by those costs, in full or in part (article 37/1, §3 of the Road Traffic Act). The fine cannot, however, go below €1. The judge only does this if you ask for it.

Because the costs have usually not yet been incurred at the time of the hearing, it is best to submit a quote from an approved service centre. If the device has to be fitted in several vehicles, say so expressly. The actual amounts are in our article on the alcohol interlock.

Handing in your licence: an alternative?

You can choose not to drive during the alcohol interlock period and to hand in your licence at the court registry. For a professional driver, this is rarely a solution: you then cannot drive the lorry or bus either.

If you also have to take medical and psychological reinstatement exams after a ban, be aware that stricter medical standards apply to C and D licences than to the B licence. For more, read our article on reinstatement exams.

Frequently asked questions

Have your case reviewed

Do you drive for a living and are you facing an alcohol interlock? We prepare the documents with you to ask for categories to be excluded or for the fine to be reduced. Contact us.

Law as at 30 September 2026. We update this article when the rules change.