Start by selecting the country you are travelling in and then find your travel company:
SNCB - Benerail
For missing items, SNCB have created the following lost and found search form: http://www.belgianrail.be/en/customer-service/lost-objects/Lost-Objects-Step1.aspx
SNCF's lost and found procedure requires you to file a report at the nearest SNCF station equipped with a lost and found service.To find a station with a lost and found service, go to www.gares-sncf.com (available in French only), select a train station from the list, then click on "Services" and then click the "Services aux voyageurs" section to find the "Objets Trouvés" (lost and found).
For missing items on routes operated by Deutsche Bahn, you can file a lost and found report at the train station. You have four weeks following the date of travel to file this report. Additionally there is an online form available that will be forwarded directly into the Deutsche Bahn lost and found database.
Frecce (Frecciarossa, Frecciargento and Frecciabianca)
If you leave your train and immediately realise that you are missing an item, there is a search service available which can be requested at the Customer Service office within the following stations: · Torino Porta Nuova · Milano Centrale · Venezia Santa Lucia · Bologna Centrale · Firenze Santa Maria Novella · Roma Termini · Napoli Centrale · Reggio Calabria Centrale
If your item is found, the Customer Service office will contact you to arrange a time and place for collection. Should the attempts of the office staff to contact you fail, the item will be taken to the local authority's office (Ufficio del Comune). In the event that your realise you are missing an item a significant amount of time after arriving at the station, then it is likely your item will have already been transported to the local authority's office (Ufficio del Comune). In such a case, you will need to contact the local authority’s office directly. You can find the telephone number for the relevant local authority office on the website of the train station you arrived at.
If you are a missing an item and you were travelling on a Regional train, then you are required to contact the relevant local authority’s office "Ufficio del Comune" directly. You can find the telephone number for the relevant local authority office on the website of the train station you arrived at.
If you are missing an item and you were travelling within Spain on a Renfe train, then you can contact the the lost and found department at the following email address and phone number: firstname.lastname@example.org; +34 902 320 320. Please note, that items found are only stored for two months.