Originally Posted by
A1pax
How do we put in a claim with Amex? Do we wait until the rental car company charged hisAmex card first?
To make a claim online please visit americanexpress.co.uk/
claims to submit your claim details. Alternatively, to report a claim
or receive assistance please call 0800 917 8054 or in a medical
emergency call +44 (0) 20 3126 4109. Please be ready to provide
your Card number, which should be used as your reference
number. Please ensure copies are kept of all documentation
relating to a claim.
Read here, section 1.5 (page 14)
https://www.americanexpress.com/uk/c...ation_v1_0.pdf
...and also page 19 "How to claim".