You can challenge a fine in transport (bus, metro, train...) if you consider that the non-presentation of your ticket was without intent to defraud. For example, you could not compost your ticket because the composting kiosks were not working.

You have 3 months to file a complaint with the carrier customer service by registered letter with a notice of receipt (its address appears on your fine).

You can use a template letter to write your mail:

Challenging a report on public transport (mail model)

National Institute of Consumer Affairs (INC)

Pour en savoir plus

If you are not satisfied with the answer or if you do not get an answer within 1 month, you can appeal to the company mediator.

For example, if it's the SNCF: titleContent :

Refer online to the SNCF Ombudsman

If it's the RATP: titleContent :

Contact the RATP Ombudsman online