Photograph every receipt immediately — before you leave the table, counter, or checkout desk.
ContextThe gap between 'transaction happened' and 'receipt is documented' should be measured in seconds. A receipt in your pocket has multiple failure modes: thermal paper fades (often unreadable within days in a warm pocket), receipts migrate to different bags, and 'deal with it later' becomes a reconstruction exercise at 11pm before a flight. Photographing before you stand up costs two seconds and eliminates the problem entirely. Angle, light, and completeness matter even now: make sure the vendor name, date, itemized amounts, and total are all visible in the frame.

