Complete Your Hauptuntersuchung (HU) and Abgasuntersuchung (AU) in Germany

The Hauptuntersuchung (HU), often colloquially known as "TÜV", is Germany's mandatory periodic technical inspection designed to ensure vehicles meet road safety and environmental standards. This crucial check, which includes the Abgasuntersuchung (AU) (emissions test), is a legal requirement for all registered vehicles to maintain their roadworthiness and environmental compliance. Successfully passing the HU results in a new HU-Plakette (inspection sticker) being affixed to your vehicle's rear number plate, validating its compliance until the next due date.

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Understanding the German Hauptuntersuchung (HU) and Abgasuntersuchung (AU)

The Hauptuntersuchung (HU) is a comprehensive technical inspection of your vehicle required by German law, specifically the Straßenverkehrs-Zulassungs-Ordnung (StVZO) and its Anlage VIII. Its primary purpose is to ensure that all vehicles operating on public roads are safe, properly maintained, and environmentally friendly. This prevents potentially hazardous or excessively polluting vehicles from endangering road users or the environment.

The Abgasuntersuchung (AU), or emissions test, is an integral component of the HU. Since 2010, the AU is no longer a separate sticker on the front license plate but is carried out as part of the overall HU. It verifies that your vehicle's exhaust emissions comply with the legal limits, contributing to cleaner air. For modern vehicles, this includes checking the On-Board Diagnostics (OBD) system for emission-related faults, alongside traditional exhaust gas measurements.

Who Conducts the HU/AU? The "TÜV" Misconception

While the term "TÜV" is often used synonymously with the Hauptuntersuchung, it's important to understand that TÜV (Technischer Überwachungsverein) is one of several officially recognized technical inspection organizations in Germany. Historically, TÜV held a monopoly on these inspections, leading to the widespread use of its name. Today, other approved providers also conduct the HU/AU.

Key official inspection providers include:

• TÜV (Technischer Überwachungsverein) - Market leader with regional branches (e.g., TÜV Süd, TÜV Rheinland).
• DEKRA (Deutscher Kraftfahrzeug-Überwachungs-Verein)
• GTÜ (Gesellschaft für Technische Überwachung)
• KÜS (Kraftfahrzeug-Überwachungsorganisation freiberuflicher Sachverständiger)

These organizations perform identical checks according to the same legal standards. You are free to choose any of these authorized service providers for your vehicle inspection.

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Mandatory Inspection Intervals and Due Dates

The frequency of the Hauptuntersuchung (HU) and Abgasuntersuchung (AU) depends primarily on the type and age of your vehicle. Adhering to these intervals is crucial, as overdue inspections can lead to penalties and potentially impact insurance coverage in case of an accident.

Standard Intervals for Common Vehicle Types

The following table outlines the general inspection intervals for typical vehicles. Specific exceptions may apply for certain commercial vehicles, agricultural machinery, or special-purpose vehicles.

Vehicle Type	First Inspection (after initial registration)	Subsequent Inspections (after previous HU)
Passenger Cars (Pkw)	36 months (3 years)	Every 24 months (2 years)
Motorcycles (Krafträder)	24 months (2 years)	Every 24 months (2 years)
Mobile Homes (Wohnmobile) up to 3,500 kg	36 months (3 years)	Every 24 months (2 years)
Mobile Homes (Wohnmobile) over 3,500 kg	24 months (2 years)	Every 24 months (2 years)
Trailers (Anhänger) up to 750 kg	36 months (3 years)	Every 24 months (2 years)
Trailers (Anhänger) over 750 kg	24 months (2 years)	Every 24 months (2 years)
Taxis, Rental Cars, Buses (Public Transport)	12 months (1 year)	Every 12 months (1 year)

The due date for your next HU is clearly indicated on the round HU-Plakette on your vehicle's rear number plate and also recorded in your Zulassungsbescheinigung Teil I (vehicle registration document, formerly known as Fahrzeugschein).

Understanding the HU-Plakette

The HU-Plakette is a circular, colored sticker on your rear number plate that displays the month and year of your next scheduled Hauptuntersuchung.

• Central Number: The large number in the center indicates the year the next HU is due.
• Top Number (12 o'clock position): The number at the very top (12 o'clock position) indicates the month the next HU is due. Imagine a clock face; if '9' is at the top, your HU is due in September.
• Color Cycle: The color of the sticker rotates every six years, allowing for quick visual identification of the due year even from a distance.
• Black Segment: A thick black segment on the outer edge of the sticker also points to the month of the next inspection, acting as an additional visual aid. For instance, if the black segment is between the 8 and 10 o'clock positions, it signifies that the HU is due in September (at the 9 o'clock mark).

Rules for Overdue Inspections

It is the vehicle owner's responsibility to ensure the HU is completed on time. The inspection must be carried out at the latest by the end of the month indicated on the HU-Plakette.

Since July 1, 2012, there is no "backdating" of the HU. This means if you are late, the next HU will still be due 24 months from the actual inspection date, not from the original overdue date. However, being overdue has consequences:

• Surcharge: If you exceed the HU due date by more than two months, an extended inspection (Ergänzungsuntersuchung) will be performed, and the inspection fee will increase by approximately 20 percent due to the higher effort involved.
• Fines and Points: Traffic controls can result in warnings, fines, and even points in Flensburg for significantly overdue inspections. These penalties increase with the duration of the delay.
• Insurance Implications: While your compulsory third-party liability insurance (Kfz-Haftpflichtversicherung) will still cover damages to other parties in an accident, your insurer might claim back a portion of the costs from you if the accident was caused by a defect that would have been identified during an overdue HU.
• Seasonal Number Plates (Saisonkennzeichen): If your HU falls within the "rest period" (Ruhezeitraum) when your vehicle is not allowed on the road, you must complete the inspection in the first month of the next operating period. For example, if your HU is due in January but your car can only be used from April, you must have the HU done in April.

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What is Checked During the HU and AU?

The Hauptuntersuchung (HU) is a thorough "non-dismantling visual, functional, and effectiveness check" of specific vehicle components. The goal is to verify compliance with the Straßenverkehrs-Zulassungs-Ordnung (StVZO) and ensure the vehicle's overall safety, legality, and environmental performance.

Examiners follow a strict checklist, covering numerous aspects of your vehicle:

1. Braking System

• Brake pads and discs: Wear, damage, and function.
• Brake lines and hoses: Leaks, corrosion, damage, and proper routing.
• Parking brake: Functionality and effectiveness.
• Brake fluid: Level and condition.
• ABS/ESP system: Functionality (warning lights).

2. Steering System

• Steering play: Excessive free play in the steering wheel.
• Steering rods and joints: Wear, damage, and secure attachment.
• Power steering: Functionality and leaks.

3. Lights and Electrical Equipment

• All exterior lights: Headlights (low and high beam), tail lights, brake lights, turn signals, hazard lights, fog lights, reverse lights, license plate lights – checked for function, alignment, and damage.
• Warning lights: Dashboard warning lights (e.g., airbag, ABS, engine management) must not be illuminated.
• Horn: Functionality.
• Wipers and washer system: Functionality and effectiveness.
• Battery: Secure mounting.

4. Tyres and Wheels

• Tyre condition: Tread depth (minimum 1.6 mm), cracks, bulges, and cuts.
• Wheel rims: Damage, corrosion, and proper fitment.
• Tyre pressure monitoring system (TPMS): Functionality (if equipped).
• Wheel bearings: Excessive play.

5. Suspension and Chassis

• Shock absorbers: Leaks, effectiveness, and damage.
• Springs: Breakage, corrosion, and secure mounting.
• Axle components: Bushings, joints, and mounts for wear or damage.
• Frame/Chassis: Significant corrosion, cracks, or damage to load-bearing structures.

6. Bodywork and Corrosion

• Body structure: Corrosion or damage that affects structural integrity or safety.
• Windscreen and windows: Cracks or damage in the driver's field of vision.
• Mirrors: Presence, condition, and secure mounting.
• Rust: Extensive rust on critical components or near safety-relevant parts.
• Interior: Seatbelts, seats, and other interior components for secure fitting and damage.

7. Environmental Items (Abgasuntersuchung - AU)

• Exhaust system: Leaks, corrosion, secure mounting.
• Catalytic converter/Particulate filter: Presence and functionality.
• Emissions measurement: Actual exhaust gas measurement (for relevant vehicles) to verify compliance with emission standards.
• On-Board Diagnostics (OBD): Reading of fault codes from the vehicle's engine management system to check for emission-relevant malfunctions.
• Engine warning lights: Any illuminated engine warning light usually leads to failure of the AU.

8. Other Equipment

• License plates: Securely fastened and legible.
• First-aid kit, warning triangle, safety vest: Presence and validity (first-aid kit expiry).
• Fluid levels: Oil, coolant, washer fluid (though often not a direct fail point, low levels can indicate neglect).

The inspection is comprehensive, aiming to identify any potential risks to road safety or the environment.

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Preparing Your Vehicle for a Successful Inspection

Adequate preparation for the Hauptuntersuchung (HU) can significantly increase your chances of passing on the first attempt, saving you time, money, and hassle. Many common defects can be easily identified and rectified before your appointment.

Essential Pre-Checks: Your HU/AU Checklist

Before heading to the inspection station, perform a thorough check of your vehicle using this checklist:

• Lights and Indicators:
  • Check all exterior lights: headlights (low beam, high beam), tail lights, brake lights, turn signals, hazard lights, fog lights (front/rear), reverse lights, and license plate lights.
  • Ensure all lights are working, clean, and free from cracks.
  • Verify correct headlight alignment (can be roughly checked against a wall, but best left to a workshop for precision).
• Tyres and Wheels:
  • Check tread depth: The legal minimum is 1.6 mm across the entire tread surface. Consider replacing tyres if they are near this limit.
  • Inspect for damage: Look for cuts, bulges, cracks, or embedded objects.
  • Check tyre pressure (including spare tyre, if applicable).
  • Ensure all wheel nuts are present and tight.
  • Examine rims for damage or significant corrosion.
• Brakes:
  • Listen for unusual noises (grinding, squealing).
  • Check brake pedal feel (should not be spongy or require excessive force).
  • Visually inspect brake pads and discs for wear through the wheel spokes if possible.
  • Check parking brake function on a slight incline.
• Windscreen and Wipers:
  • Inspect windscreen for cracks or stone chips in the driver's field of vision.
  • Check wiper blades for wear and effectiveness; replace if streaky.
  • Ensure washer fluid reservoir is topped up and the spray jets work correctly.
• Mirrors:
  • Check all mirrors (interior and exterior) for damage and secure mounting.
• Horn:
  • Verify the horn is working.
• Safety Equipment:
  • Ensure a valid first-aid kit, warning triangle, and safety vest are present and easily accessible. Check the expiry date on the first-aid kit.
• Fluids:
  • Check oil, coolant, and brake fluid levels. Top up as necessary.
• Exhaust System:
  • Listen for unusual exhaust noises (indicating leaks).
  • Visually inspect the exhaust for rust holes or loose mounting.
• Engine Warning Lights:
  • Ensure no engine warning lights (e.g., Check Engine Light, ABS, Airbag, ESP) are illuminated on the dashboard when the engine is running. These are almost always an immediate failure point for the HU/AU.
• General Cleanliness:
  • A clean vehicle suggests good maintenance and allows inspectors to see components clearly.

Documents to Bring to the Inspection

When you present your vehicle for the HU/AU, you typically need to bring:

• Zulassungsbescheinigung Teil I (Vehicle Registration Document Part I): This document (formerly known as Fahrzeugschein) contains all essential technical data about your vehicle and proves its registration.
• Previous HU Report (Optional but Recommended): While not strictly mandatory for the inspection itself, having the previous HU report can be useful for the inspector, especially if specific "Hints" (Hinweise) were noted previously.
• AU Certificate (if performed separately): If you had the Abgasuntersuchung (AU) performed by an authorized workshop before the HU, you must bring the official AU certificate. Note that the AU certificate must not be older than one month at the time of the HU.

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The Hauptuntersuchung and Abgasuntersuchung Process

The process of getting your vehicle inspected is relatively straightforward once you've prepared adequately.

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Understanding HU Inspection Results and Defect Categories

The inspector will classify any detected defects into specific categories, which determine whether your vehicle passes the HU and what subsequent actions are required. Understanding these categories is crucial.

Mängelklassen (Defect Categories)

The "HU-Richtlinie" (HU Guideline) defines the following classifications for findings:

Summary of Defect Categories and Consequences

Defect Category	Description	HU-Plakette Issued?	Re-Test Required?	Driving Permitted?	Action Required
Ohne Mängel	No defects found.	Yes	No	Yes	None, continue driving
Geringe Mängel (GM)	Minor defects, no immediate hazard.	Yes	No	Yes	Repair promptly
Erhebliche Mängel (EM)	Significant defects, traffic hazard or environmental impact.	No	Yes (within 1 month)	Yes, but repair immediately	Repair and present for re-test within 1 month, or face new HU.
Gefährliche Mängel (VM)	Direct & immediate traffic hazard or environmental impact.	No	Yes	No, unless directly to repair shop on shortest route	Repair immediately and present for re-test.
Verkehrsunsicher (VU)	Direct & immediate traffic hazard, immediate prohibition from driving. Old Plakette removed. Authority informed.	No	Yes (full new HU)	No, vehicle immobilized (trailer/towed only to repair)	Extensive repair, full new HU. Zulassungsbehörde is informed.

The Re-Test (Nachprüfung) Process

If your vehicle receives "Erhebliche Mängel", "Gefährliche Mängel", or is classified as "Verkehrsunsicher", you must undergo a re-test (Nachprüfung).

• Deadline: You generally have one month from the date of the original HU to have the defects rectified and present your vehicle for the re-test.
• What is re-checked: During the Nachprüfung, the inspector will only re-examine the specific defects noted in the original report. This is usually quicker and cheaper than a full HU.
• Missing the deadline: If you fail to present your vehicle for the re-test within the one-month period, the initial inspection report becomes invalid. You will then need to undergo a completely new Hauptuntersuchung, incurring the full cost again.
• Immediate Repairs: Even though there's a one-month window for the re-test, all "erhebliche" or "gefährliche" defects should be repaired immediately to ensure road safety and avoid further legal issues.

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The HU-Plakette (Inspection Sticker) and its Meaning

The HU-Plakette is the official visible proof that your vehicle has successfully passed the Hauptuntersuchung and is deemed roadworthy. This round, colored sticker is affixed to the rear number plate of your vehicle. It is a critical indicator for both you and law enforcement regarding the due date of your next inspection.

How to Read Your HU-Plakette

As discussed earlier, the HU-Plakette provides vital information:

• Year in the Middle: The large number prominently displayed in the center of the sticker indicates the year in which your next HU is due. For example, if it's a '26', your vehicle's next inspection is due in 2026.
• Month at 12 O'Clock: The number positioned at the very top of the sticker, corresponding to the 12 o'clock position on a clock face, shows the month of the due date. For instance, if '9' is at the top, your HU is due in September of the year indicated in the center.
• Black Segment: A thick, black segment on the outer edge of the sticker provides a quick visual reference for the due month. This segment is always positioned at the '12' for the current year, and then rotates clockwise to indicate the month of the next inspection. For example, if the segment points to the '9' (as per the clock face analogy), the HU is due in September. This is useful for police checks from a distance.
• Color Cycle: The color of the HU-Plakette changes in a fixed six-year cycle (Blue, Yellow, Brown, Pink/Rosa, Green, Orange). This allows a rapid visual assessment of the due year, even without reading the central number. For example, if the current year's sticker is blue, the one due in six years will also be blue.

What Happens When You Pass

Upon successful completion of the HU/AU, the inspector will:

1. Affix a new HU-Plakette to your rear number plate, oriented correctly to indicate the next due month at the 12 o'clock position.
2. Provide you with an official inspection report (Prüfbericht). This report details the findings, confirms the successful inspection, and records the new due date. Keep this report in your vehicle, or with your vehicle documents, as it serves as proof of a valid inspection.
3. Electronically transmit the data to the Kraftfahrtbundesamt (KBA), making the HU report digitally accessible via QR code, individual link, or report number. The paper form remains valid.
4. Stamp and sign your Zulassungsbescheinigung Teil I, confirming the new HU validity period.

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Costs, Fees, and Penalties for Overdue Inspections

The cost of a Hauptuntersuchung (HU) with integrated Abgasuntersuchung (AU) can vary, and being overdue incurs additional expenses and potential penalties.

HU/AU Costs

The fees for the HU and AU are not centrally fixed but are set by the individual inspection organizations (TÜV, DEKRA, GTÜ, KÜS) and can also differ slightly by region and vehicle type (e.g., car vs. motorcycle vs. heavy vehicle).

• Factors influencing cost:
  • Vehicle type: Cars are generally cheaper than heavy goods vehicles or mobile homes.
  • Region: Prices can vary between federal states (Bundesländer) and even within different locations of the same provider.
  • Provider: While competitive, there can be minor differences between TÜV, DEKRA, GTÜ, and KÜS.
  • Optional pre-checks: If you opt for a pre-inspection check at a workshop, this is an additional service.
• Average Cost (Estimate): For a standard passenger car, the combined HU/AU typically ranges from €100 to €150. Always verify current prices directly with your chosen inspection provider.

Costs of a Re-Test (Nachprüfung)

If your vehicle fails the initial HU due to significant defects (Erhebliche Mängel or Gefährliche Mängel), you will need to pay for a re-test after repairs.

• Re-test fee: This is significantly lower than a full HU, as only the rectified defects are re-checked. It typically ranges from €15 to €30, depending on the provider and the complexity of the re-check.
• Full new HU: If you miss the one-month deadline for the re-test, you will have to pay for a full new HU, incurring the standard cost again.

Penalties for Overdue Inspections

Driving with an overdue HU-Plakette is an administrative offense (Ordnungswidrigkeit) and can lead to fines and points in Flensburg. The penalties increase the longer the HU is overdue.

Overdue Period (for Cars/Motorcycles/Light Trailers)	Penalty
Up to 2 months overdue	No fine (warning possible)
2 to 4 months overdue	€15 fine
4 to 8 months overdue	€25 fine
More than 8 months overdue	€60 fine and 1 point in Flensburg

For commercial vehicles and vehicles subject to a safety inspection (Sicherheitsprüfung), the penalties for overdue inspections are generally higher and start earlier.

Additionally, if your HU is overdue by more than two months, the inspection itself will be extended to include an "Ergänzungsuntersuchung," which usually results in a 20% surcharge on the standard HU fee.

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Common Pitfalls and How to Avoid Them

Failing the Hauptuntersuchung (HU) or incurring unnecessary costs often comes down to a few common mistakes or overlooked details. Being aware of these can save you time, money, and stress.

Here are some common pitfalls and practical remedies:

1. Overlooking the Due Date:
   • Pitfall: Not knowing when your HU/AU is due and letting the deadline pass.
   • Remedy: Regularly check your HU-Plakette and Zulassungsbescheinigung Teil I. Many inspection providers (TÜV, DEKRA, etc.) and workshops offer free reminder services (via email, SMS, or post) – sign up for one!
2. Ignoring Warning Lights:
   • Pitfall: Driving with an illuminated engine warning light, ABS light, airbag light, or other critical system warning.
   • Remedy: Address any illuminated warning lights immediately. Most active warning lights indicating a system malfunction will result in an automatic HU failure, especially for emission-related or safety systems. Have your vehicle diagnosed and repaired by a specialist workshop.
3. Neglecting Minor Issues:
   • Pitfall: Thinking small issues like a burnt-out bulb, worn wiper blades, or a cracked mirror won't matter.
   • Remedy: Conduct a thorough self-check using the checklist provided earlier. Fix all obvious, minor defects before the appointment. These small items can quickly add up to "Geringe Mängel" or even "Erhebliche Mängel" if severe.
4. Worn Tyres:
   • Pitfall: Tyres with insufficient tread depth or visible damage.
   • Remedy: Ensure all tyres (including the spare, if applicable, and if subject to inspection) have a minimum tread depth of 1.6 mm. Check for cracks, bulges, or embedded objects. Replace worn or damaged tyres before the HU.
5. Brake System Issues:
   • Pitfall: Squealing brakes, a soft brake pedal, or visible wear on discs/pads.
   • Remedy: Have your brakes inspected and serviced if you notice any unusual noises, reduced braking performance, or a spongy pedal. Ensure brake fluid is at the correct level.
6. Faulty Lighting:
   • Pitfall: Driving with a single broken headlight or tail light.
   • Remedy: Systematically check every light function on your vehicle. Replace any defective bulbs. Ensure headlight alignment is correct.
7. Exhaust System Leaks/Damage:
   • Pitfall: A noisy exhaust or visible rust holes.
   • Remedy: Repair any leaks or damage to the exhaust system. A leaking exhaust can lead to higher emissions readings and failure of the AU.
8. Missing or Expired Safety Equipment:
   • Pitfall: Not having a first-aid kit, warning triangle, or safety vest, or having an expired first-aid kit.
   • Remedy: Ensure all mandatory safety equipment is present, easily accessible, and in good condition. Check the expiry date on your first-aid kit.
9. Missing the Re-Test Deadline:
   • Pitfall: Failing the initial HU and then not returning for the re-test within the one-month window.
   • Remedy: If your vehicle receives "erhebliche Mängel," get the repairs done immediately and book the re-test within the specified month. Missing this deadline means you'll have to pay for a full new HU, not just the cheaper re-test.
10. Poor Maintenance History:
    • Pitfall: A generally neglected vehicle with visible signs of poor maintenance.
    • Remedy: Regular servicing and proactive maintenance are the best ways to ensure your vehicle remains roadworthy. A well-maintained vehicle is far more likely to pass the HU without issues.

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What Happens After Passing the HU/AU?

Successfully completing the Hauptuntersuchung (HU) and Abgasuntersuchung (AU) brings immediate benefits and certain responsibilities.

New HU-Plakette

The most visible sign of a passed inspection is the application of a new, round HU-Plakette to your vehicle's rear number plate. This sticker clearly displays the month and year of your next scheduled inspection. The new Plakette effectively replaces the old one and certifies that your vehicle meets all necessary safety and environmental standards for the next inspection cycle (typically 24 months for passenger cars).

The Official Inspection Report (Prüfbericht)

After passing, you will receive a detailed inspection report (Prüfbericht). This document is crucial and should be kept safely, ideally with your vehicle's other important papers (like the Zulassungsbescheinigung Teil I).

The report includes:

• Confirmation of the successful HU/AU.
• The date of the next due inspection.
• A list of any "Hinweise" (hints) or "Geringe Mängel" (minor defects) noted by the inspector. While these don't prevent you from getting the Plakette, you are legally obligated to rectify any minor defects promptly.
• The inspector's signature and the stamp of the inspection organization.

The HU report is also digitally accessible via a QR code, individual link, or by entering the report number.

Recording in Vehicle Registration Documents

The successful HU will be recorded in your Zulassungsbescheinigung Teil I (vehicle registration document Part I), usually by a stamp and signature, indicating the new validity period of your vehicle's inspection. This formal entry confirms the vehicle's continued registration eligibility.

What if You Sell the Vehicle?

If you decide to sell your vehicle after passing the HU/AU, the valid inspection is a significant selling point. The new owner will benefit from the current roadworthiness certificate. You will pass on the inspection report and the updated Zulassungsbescheinigung Teil I to the buyer.

What if There are Delays or Rejection?

• Delays: If for any reason the inspection process takes longer than expected, or if there are administrative delays, ensure you have a written confirmation of your appointment and the inspection status. However, delays are rare if you schedule in advance.
• Rejection (Failed HU): As detailed in the "Defect Categories" section, if your vehicle fails the HU, you will not receive a new Plakette. You must address the defects and undergo a re-test within one month. Driving a vehicle classified as "Verkehrsunsicher" is strictly prohibited, and the existing Plakette will be removed, with the Zulassungsbehörde (vehicle registration authority) being informed.

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Glossary of Key Terms

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Official Sources and Further Information

For the most current and authoritative information regarding the Hauptuntersuchung (HU) and Abgasuntersuchung (AU) in Germany, always refer to the official sources.

• ADAC (Allgemeiner Deutscher Automobil-Club): Provides comprehensive guides and advice for vehicle owners. Look for their "HU und AU" sections.
  • ADAC - HU und AU Guide
  • ADAC - How to Read TÜV-Plakette
  • ADAC - Overdue or Failed HU
• TÜV-Verband (Association of Technical Inspection Agencies): The umbrella organization for TÜV companies, offering general information on vehicle safety and inspections.
  • TÜV-Verband Official Website
• DEKRA: Another major official inspection organization.
  • DEKRA Official Website
• GTÜ (Gesellschaft für Technische Überwachung): Another officially recognized inspection organization.
  • GTÜ Official Website
• KÜS (Kraftfahrzeug-Überwachungsorganisation freiberuflicher Sachverständiger): Another officially recognized inspection organization.
  • KÜS Official Website
• Straßenverkehrs-Zulassungs-Ordnung (StVZO): The core legal text governing vehicle licensing and technical requirements in Germany.
  • StVZO on gesetze-im-internet.de (German official legal portal)

When seeking information, specifically look for pages titled "Hauptuntersuchung," "Abgasuntersuchung," "Fristen," "Mängelklassen," or "TÜV-Plakette" on these official websites.

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