The NMFC (National Motor Freight Classification) has made changes to the window of time you have to report damage to freight carriers. Concealed damages to your shipment previously could have been reported within 15 days of delivery, but as of April 18, 2015 damage must be reported within 5 business days of delivery. Concealed damage refers to any damaged that was not able to be seen at the time of delivery. If 5 business days pass between delivery and the reporting of damage (or request for inspection by the buyer), it is up to the buyer to provide evidence that damage was not incurred after the shipment had been delivered. Call to report any damage you see on your shipment to the freight company as soon as it is noticed. Be sure to leave the shipping container and its contents in the same condition as when the damage was discovered (as much as possible) so a proper inspection can be done.
Read the entire document from the NMFC – Supplement 1 to NMF 100-AO