Can this update be done on the same EPREL registration number (for registered tires) or does the product need a new registration?

If the change is exclusively the HL prefix and no parameter values indicated in the label of PIS is changed, please update the tyre size designation with the HL prefix. In the justification just write: 'Added HL indication, to fully match the indication on the sidewall' or similar text.

If, on the contrary, also any value in RR, wet grip, noise, etc. changes, the tyre should be registered as a new product.

_{Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.}