Hello,
I find that the almost sole use for me of receipts are warranties.
I would love to see a feature that whiles uploading a receipt picture you can tell how long the warranty is for.
Do most places accept a picture of a receipt for a warranty, exchange or return? I suppose that for a return it might be an issue… no idea. 
Best,
AT
This could be pretty cool for when we have the marketplace.
For example: say I purchased a TV from John Lewis using my Monzo Account. I could upload a receipt and tell the app when my warranty is due to expire. Then a few weeks before, maybe Monzo could suggest a third party who I could extend the warranty through for x amount? It would also be good to see the warranty information within the transaction too.
Not sure if they are third party warranty companies but! 
Cool idea!
I imagine this would work through receipts OCR
I think you just need proof of purchase. If the photo is legible, they should accept it. In theory a bank statement might be enough in some circumstances. It will depend on the attitude of the store or staff, I suppose