You are here:

Modify registration certificate I - technical modification

In the event of technical modifications to the motor vehicle or trailer, the operating permit for the vehicle may expire. An assessment by an officially recognized expert for motor vehicle traffic is required as proof of compliance with the regulations. A new operating permit is issued by the registration authority after the expert opinion.

If the conformity is proven by a general type approval (ABE) for vehicle parts or a parts certificate, an acceptance confirmation is required, which may be the basis for the correction of the registration certificate part I (old vehicle registration document) and the registration certificate part II (old vehicle title) by the registration authority. This does not apply to vehicle parts if the ABE does not stipulate an acceptance requirement.

Before installation or modification, an officially recognized expert for motor vehicle traffic or a test engineer from a monitoring organization should be consulted as to whether the operating permit will be affected or whether the modification can be approved at all and thus a positive opinion for a new operating permit can be issued.

Certain technical modifications must be reported to the registration authority without delay and, depending on the type of modification and the evidence, must be inspected beforehand by the Technical Inspection Agency or an approved testing organization (TÜV, DEKRA, GTÜ, KÜS, GTS, FSP). This includes for example:

  • Changes to the vehicle class or the vehicle and body type
  • Changes in engine capacity, rated power, fuel type or energy source
  • Increase of the maximum design speed
  • Reduction of the maximum design speed, if this is relevant for the driving license or registration
  • Modification of the permissible axle loads, the total mass, the support load or the trailer load
  • Increase in vehicle dimensions, except for passenger cars and motorcycles
  • Change in the number of seats or standing places for buses and coaches
  • Changes in exhaust or noise levels, provided they affect motor vehicle taxes or traffic bans
  • Use of other wheel/tire combinations

What documents do I need?

  • Valid identity card, passport or electronic residence permit (eAT) as well as the original national passport of the vehicle owner applying for the permit
  • in case of representation with written power of attorney

    Additionally: identity card or passport of the authorized person

  • Registration certificate part I or vehicle registration document
  • Registration certificate part II or old vehicle registration document
  • Expert opinion or operating licence of the parts manufacturer
  • Confirmation of acceptance by an approved testing organisation


  • valid test report on a general inspection


  • Expert opinion or manufacturer's certificate
  • licence plates, if applicable

    In the case of some technical changes affecting the total weight, the main inspection periods of the vehicles concerned may also change and the main inspection sticker must therefore be reaffixed accordingly.

  • if registered to companies

    - Current and valid business registration and, if available, current and valid excerpt from the commercial register (also as a copy)
    - Power of attorney, if the person authorized to dispose does not personally submit the application on site