Many vehicle owners in Portugal wrongly think that passing the periodic inspection means all modifications made to the car are automatically legalized. However, according to Decree-Law No. 144/2012, the periodic inspection only confirms the operating and safety conditions of vehicles, having as reference the original homologated characteristics or those resulting from a previously authorized transformation.
The legislation clearly distinguishes the periodic inspection from the procedures of authorization, homologation, extraordinary inspection, and endorsement required when the characteristics of a vehicle are altered. Article 115 of the Road Code considers any transformation to be any alteration of the constructive or functional characteristics of a vehicle, including modifications to the structure, bodywork, engine, systems, or components.
As an example, IMT clarifies that the installation of colored films on windows requires these to be homologated, with a legible and permanent homologation mark, and also requires approval of the vehicle in an extraordinary inspection and the subsequent endorsement on the registration certificate. Similarly, replacing wheels with dimensions different from those authorized for the vehicle may require an endorsement, upon declaration of the official representative of the brand or an accredited laboratory.
The Road Code provides a fine between 250 and 1,250 euros for unauthorized transformations, with vehicle seizure also applied until approval in extraordinary inspection. IMT recommends that, before making any significant modification to the vehicle, the owner confirm with this entity which procedure applies to ensure the alteration is legally regularized.
