There could be a QR or other machine readable code on the card that on scanning will take the user to a secure page with a basic set of options, namely:
- One click Report Lost.
- Report lost with Feedback - so say if the whole wallet was found, then this can be noted/relayed.
- Link to customer service contact details, or direct link to tel:number. Something a user will need in a rush, and has the potential to change. Plus depending on the region of scanning, the displayed number can be changed.
Only Monzo knows what UID refers to what customer, thus without leaking any more info than available on the card this reduces the hassle for a good samaritan.
I got the thought while reading this post.