German HU and Emissions Testing on Import Stock: What Dealers Actually Have to Plan Around in 2026
20 September 2026
A used car imported from another EU country does not automatically need a fresh German Hauptuntersuchung (HU) — the periodic roadworthiness inspection. Germany is required to recognise a valid roadworthiness certificate issued in another Member State — but only while that certificate is still valid measured against German inspection intervals, and Germany’s intervals are shorter than the EU minimum. That single mismatch decides whether a unit goes from transporter to registration desk in days, or waits for a test slot.
The second thing worth correcting before you plan a quarter of stock: there is no German rule dated 2025 that introduced systematic emissions measurement at the HU. The change that actually catches import stock is older and narrower — particle number counting on Euro 6/VI diesels, mandatory in the Abgasuntersuchung (AU) — the German exhaust emissions test — since 1 July 2023. The genuinely new item from 2025 is at EU level, is not in force, and should not be in your 2026 process yet.
This is written for dealers and importers buying M1 and N1 stock in Benelux, France and Italy for resale in Germany and Austria. It is about the order in which you do things, not about what to say at the counter when it has already gone wrong.
What you’ll read
- Does an imported car need a new German HU before it can be registered?
- Which emissions test will your Euro 6 diesel stock actually face?
- Where does the HU sit on the import timeline — and what is the short-plate trap?
- What does the COC decide before the inspection even starts?
- What changes in 2027 and what is still only a proposal?
Does an imported car need a new German HU before it can be registered?
Not necessarily. Article 8(3) of Directive 2014/45/EU obliges every Member State to recognise a roadworthiness certificate issued by another Member State on re-registration, “as if it had itself issued that certificate, provided that the roadworthiness certificate is still valid in terms of the frequency intervals established for periodic roadworthiness tests by the re-registering Member State.”
Read the condition carefully, because that is where the money is. The test is not “is the certificate still valid in the country that issued it”. The test is “would Germany still consider the vehicle inside its own inspection interval”. Those are different questions, and for a large share of Benelux and French stock they give different answers.
Germany’s intervals for a passenger car are set in Anlage VIII No. 2.1.2.1 of the Straßenverkehrs-Zulassungs-Ordnung (StVZO), the German vehicle registration and licensing regulation: first Hauptuntersuchung 36 months after first registration, then every 24 months. The EU minimum in Article 5(1)(a) of Directive 2014/45/EU is more relaxed — four years, then every two. Several source markets apply exactly that minimum.
| Source market | First periodic test due | Then | Legal basis |
|---|---|---|---|
| Germany | 36 months after first registration | every 24 months | Anlage VIII No. 2.1.2.1 StVZO |
| Austria | 36 months | +24 months, then annually (“3-2-1”) | §57a KFG |
| Netherlands — petrol / electric | 48 months | every 24 months until age 8, then annually | RDW (APK) |
| Netherlands — diesel / LPG | 36 months | annually | RDW (APK) |
| Belgium | by the 4th anniversary | annually (2-yearly option under 100,000 km until age 6) | GOCA / periodieke keuring |
| France | in the 6 months before the 4th anniversary | every 24 months | contrôle technique périodique |
| EU minimum | 4 years | every 2 years | Dir. 2014/45/EU, Art. 5(1)(a) |
Three consequences that show up on a stock list, not in a legal summary:
A 37- to 47-month-old petrol car from the Netherlands, Belgium or France has never been tested. It has no certificate at all, because in its home market nothing was due yet. Germany wanted the first HU at 36 months. That unit needs a German HU before it can be registered, full stop — and on a lot of near-new lease returns, that is precisely the age band you are buying.
A Dutch diesel is usually the easy case. First APK at 36 months and annually after that means a Dutch diesel almost always carries a certificate that is comfortably inside Germany’s 24-month window.
A Belgian or French car older than four years depends on when the last test was done, not on whether it has expired at home. Belgium runs annual inspections from year four; Germany runs 24-month intervals. A Belgian certificate that is 14 months old is expired in Belgium and still inside the German frequency. The directive text points one way here. Whether a given Zulassungsstelle (the local vehicle registration office) applies it that way in practice is a question for that office, and offices differ — the City of Munich registration office, for example, publishes that it recognises test reports from EU countries for vehicles with EC type approval, subject to the report containing the VIN, test date, mileage, defects found and outcome. Confirm with the destination office before you build a delivery date on it, and get the foreign report in a form that carries those five data points.
One thing that is not optional either way: for a vehicle with EU type approval being registered in Germany for the first time, the office wants the Certificate of Conformity. Without EU type approval evidence, the file moves to a §21 StVZO expert report — per vehicle, by appointment, priced per vehicle. Our checklist on buying from a German car dealer covers the document set to collect at purchase; the full list of failure points sits in 7 reasons your car registration was rejected.
Which emissions test will your Euro 6 diesel stock actually face?
Since 1 July 2023, every Euro 6/VI diesel presented for the German Abgasuntersuchung goes through particle number counting rather than the old opacity measurement. The pass limit is 250,000 particles per cm³ of exhaust, with a fast-pass at 50,000 cm⁻³ on the first measurement segment. Older diesels — Euro 5 and below — still go through the opacity route.
This is the rule that fails import stock, and it is worth being precise about what it measures. Opacity measurement judged smoke density and was forgiving of a partially degraded diesel particulate filter. Particle counting does not judge smoke, it counts particles, and a DPF that is cracked, removed, badly regenerated or fitted with a low-quality replacement shows up immediately. A car that would have passed the AU on opacity in 2022 can fail the same test today with no change to the vehicle.
| Emission class (diesel) | AU measurement method | What typically fails it | Practical exposure on import stock |
|---|---|---|---|
| Euro 6 / Euro VI | Particle number counting, limit 250,000 cm⁻³ | Damaged, removed or poorly repaired DPF; failed regeneration cycles | High — this is the bulk of 2015+ stock |
| Euro 5 | Opacity (turbidity) measurement | Heavy smoke, injection and EGR faults | Moderate |
| Euro 4 and older | Opacity (turbidity) measurement | Same, wider tolerances | Lower, but units are older |
| Petrol, all classes | OBD readout plus exhaust gas measurement, no PN counting today | Catalyst and lambda faults, stored OBD codes | Low |
Two operational points follow.
First, this is a purchase-side check, not a registration-side one. A DPF problem is a workshop cost and a workshop lead time, not a paperwork cost. If you are buying diesel stock at auction or dealer-to-dealer, the emission class and the DPF history belong in the inspection you do before you bid, because after the hammer it is your repair. Reading the emission class takes seconds — it is in the source registration document and in the COC.
Second, ignore anything you read about a 2025 German tightening. There was none for passenger cars. What is genuinely scheduled is the revised AU-Richtlinie together with AU-Leitfaden 7, which German trade bodies now expect no earlier than 1 January 2027 after the originally planned 2026 date slipped. Guideline 6 remains the operative document. If a supplier or a workshop tells you new AU device rules took effect in late 2025, that is not correct.
Where does the HU sit on the import timeline — and what is the short-plate trap?
The HU is not the last step before registration. On German import logistics it is frequently the first step, because since 1 April 2015 a Kurzzeitkennzeichen — the German short-term plate used to move unregistered vehicles — is only issued on proof of a valid HU. The single exception registration offices apply is a journey to the nearest competent testing station.
That rule quietly reorders the whole process. A dealer who plans to collect a unit in Rotterdam, drive it to the yard on a short-term plate, prepare it and then book the HU discovers that the plate was never available. Either the vehicle arrives on a transporter, or it moves on the dealer’s own red trade plate (06er), or the only permitted trip on a short-term plate is the one to the test station.
A sequence that holds together, with the constraint respected:
| Day | Action | Why here and not later |
|---|---|---|
| 0 — purchase agreed | Collect VIN list, source registration document, existing PTI report, emission class | Everything below depends on data you can only get cheaply now |
| 0 | Order any missing Certificate of Conformity | Processing runs in parallel with transport instead of after it |
| 0–2 | Decide the movement method: transporter, trade plate, or short-term plate with a valid HU | The 1 April 2015 rule is a hard gate, not a formality |
| 1–3 | Book the HU slot for units whose foreign certificate Germany will not accept | Test capacity, not paperwork, is the bottleneck in most regions |
| on arrival | HU and AU, then preparation | A failed AU converts into workshop time you can still absorb |
| after file is complete | Book the Zulassung appointment | An appointment booked on an incomplete file is an appointment you lose |
Two cost lines worth knowing before you leave a unit standing with a lapsed inspection date. Where the HU is overdue by more than two months, the German fee schedule provides for an extended inspection with a surcharge of around 20 % on the regular HU fee. And if the vehicle is driven on public roads in that state, the standard penalty scale applies: €15 for 2–4 months overdue, €25 for 4–8 months, and €60 plus one point in Flensburg beyond eight months. Small numbers individually. On a yard of thirty units with drifting dates, they stop being small, and the point entry attaches to a driver, which on trade plates is your staff.
For the general pattern of what delays a registration file across markets, see our breakdown of the 5 most common reasons registration offices reject your COC.
What does the COC decide before the inspection even starts?
The Certificate of Conformity is where the registration office takes the emission class and the CO₂ figure from — and those two values decide the vehicle’s German motor tax band, its environmental sticker category, and which AU procedure the test station applies. Get them wrong on paper and you have not just a document problem; you have a vehicle priced on the wrong tax assumption.
The chain is short and mechanical:
- The COC states the type approval, the emission class and the CO₂/consumption values for that specific VIN.
- The Zulassungsstelle transcribes them into Zulassungsbescheinigung Teil I. Our field-by-field walkthrough of the EU vehicle registration certificate shows where each value lands.
- The emission key derived from that data drives the tax band and the sticker.
- The class recorded there is also what tells the test station whether the AU runs particle counting or opacity.
Which is why “the COC is missing but the car is fine” is an expensive sentence. A missing or non-original certificate is one of the most common reasons a file stalls, and registration offices work from the manufacturer’s original or a manufacturer-issued duplicate, not from a scan inherited from a previous owner. Our note on what authorities actually check in a COC lists the fields that get files sent back, and the complete Certificate of Conformity guide explains the document structure.
Where a certificate is genuinely missing, the cost of closing the gap is a line item you can price at the negotiation table instead of absorbing three weeks later. Certificate prices for common DACH stock, read from our live catalogue on 22 August 2026 — all figures net, excl. VAT, invoiced under reverse charge for EU-registered businesses:
| Brand | PDF (net, excl. VAT) | Printed original (net, excl. VAT) |
|---|---|---|
| Volkswagen | €134 | €144 |
| Audi | €134 | €144 |
| BMW | €174 | €184 |
| Mercedes-Benz | €234 | €244 |
| Porsche | €294 | €304 |
Lead times are brand-dependent — many certificates are issued within a few working days, some take up to two weeks, and the printed original ships after the PDF is released. Our article on how long a COC takes and what influences the timeline sets out which factors move the date. The operational rule is unchanged: order on the purchase day, not on arrival, and the processing time disappears inside the transport window instead of adding to standstill.
What changes in 2027 and what is still only a proposal?
Two confirmed changes land in 2027 — Austria’s inspection intervals move to a 4-2-2-2-1 pattern on 19 May 2027, and Germany’s revised AU-Richtlinie is expected no earlier than 1 January 2027 — while a much larger EU roadworthiness package is only a proposal and should not be planned against yet.
Confirmed, Austria, 19 May 2027. The §57a inspection interval for cars, motorcycles and trailers up to 3.5 t moves from the current 3-2-1 pattern to 4-2-2-2-1: first inspection four years after first registration, then two-yearly intervals, then annual. For anyone remarketing between Germany and Austria, this widens the gap between the two national intervals — and since Article 8(3) recognition is measured against the intervals of the receiving country, a change on either side of the border changes which certificates travel.
Expected, Germany, no earlier than 1 January 2027. The revised AU-Richtlinie and AU-Leitfaden 7. The revision clause under discussion covers whether the PN test procedure and limit values need adjusting, and the replacement of manufacturer target data with statutory AU target values for petrol and diesel engines from Euro 5 downward. Until it is published, Guideline 6 applies.
Proposed, EU level, not in force. On 24 April 2025 the European Commission published its roadworthiness package — COM(2025) 179 and COM(2025) 180 — revising the periodic testing and vehicle registration framework. The Council agreed its position on 4 December 2025. The elements that would matter to a used-car importer are:
| Element in the 2025 proposal | What it would change for import stock |
|---|---|
| Particle number measurement and NOx measurement added to the PTI test items | Extends PN counting beyond today’s Euro 6/VI diesel scope |
| Annual inspection for cars and light commercial vehicles from 10 years after first registration | Shortens intervals on older stock and changes the Art. 8(3) recognition arithmetic |
| Annual emissions inspection for light commercial vehicles from one year after first registration | Direct impact on N1 fleet remarketing |
| Digitalisation of vehicle registration documents and cross-border data exchange | Would reduce the paper dependency of re-registration over time |
None of this is applicable law in August 2026, and none of it should appear in a stock valuation yet. The reason to track it is that the proposal moves in one direction — more measurement, shorter intervals, more cross-border data — and diesel stock you buy today may face a stricter test at its second or third resale than at its first.
Note on sources: The final adopted text, transposition deadlines and any transition periods for the 2025 roadworthiness package could not be confirmed at an official source at the time of writing; the Council press release of 4 December 2025 was not retrievable. Treat the table above as the content of the proposal and the Council position, not as settled law. Reports that France introduced particle counting in its contrôle technique in 2025 or 2026 could not be confirmed on the French ministry’s official page and are not asserted here.
Preparing a lot of import stock for the German market?
We supply Certificates of Conformity in volume to dealers, importers and registration agencies across DACH and Benelux — send a VIN list and the destination market, and you get per-brand lead times and per-unit pricing for the volume, so the document side runs in parallel with transport instead of behind it.
All quotes net, excl. VAT, invoiced under reverse charge for EU-registered businesses. No call centre and no phone queue: everything runs in writing, per VIN list.
Request a volume quote → · Checking a single unit before you bid? Start with the VIN check.
Sources
- Directive 2014/45/EU on periodic roadworthiness tests — Article 5(1)(a) (test frequency for M1 and N1), Article 8(3) (recognition of a roadworthiness certificate on re-registration in another Member State). EUR-Lex, CELEX 32014L0045.
- Straßenverkehrs-Zulassungs-Ordnung (StVZO), Anlage VIII No. 2.1.2.1 and §29 — German HU intervals (36 months, then 24 months) and periodic monitoring of vehicles. gesetze-im-internet.de.
- Change to the directive for carrying out the exhaust emissions test under No. 6.8.2 of Annex VIIIa StVZO (AU-Richtlinie) — particle number counting for Euro 6/VI diesel vehicles, mandatory from 1 July 2023, pass limit 250,000 cm⁻³, fast-pass 50,000 cm⁻³ (German professional press: Krafthand, autoservicepraxis, amz).
- Kraftfahrzeug-Zulassungsverordnung, Kurzzeitkennzeichen rules in force since 1 April 2015 — valid HU required for issue, exception for the journey to the nearest testing station (published guidance of German registration offices, e.g. Stadt Emden, Fachdienst 433).
- Penalty scale for an overdue HU under §29 StVZO: €15 (2–4 months), €25 (4–8 months), €60 plus one point (over 8 months); extended inspection with approx. 20 % fee surcharge beyond two months.
- §57a KFG (Austria) — current 3-2-1 interval; change to 4-2-2-2-1 from 19 May 2027 (WKO, ÖAMTC).
- Landeshauptstadt München, vehicle registration office — document requirements for registering a vehicle imported from abroad, including COC for EU type-approved vehicles and conditions for recognising EU test reports.
- COM(2025) 179 final and COM(2025) 180 final, European Commission, 24 April 2025 — roadworthiness package proposals; Council general approach, 4 December 2025.
- ASA-Verband / German trade press — revised AU-Richtlinie and AU-Leitfaden 7 expected no earlier than 1 January 2027.
- coc-auto.eu live catalogue, prices read 22 August 2026 (net, excl. VAT).