Just landed somewhere away from home without my bag. Luckily that ticket was purchased with my AMEX card which gives 750 British pounds in spending allowence for the next 24 hours.

However, this is not clearly stated anywhere, do you guys think Finnair would provide 750+ quid allowence for an 36 hours baggage delay? In which case I shall claim it directly through Finnair.

I understand that I cannot claim purchases nor be compensated by two parties without violating some law. If Finnair agrees to provide an one time compensation, ie in form of travel voucher or payment, does this clash the 'essentials purchases reimbursements' provided by AMEX? Is it legal to claim my expenses with AMEX and accept an EU261-style compensation from Finnair?

Any input is very welcomed