I've posted about this one before, but I use an older scanner. A Cannon LIDE 50.
I got it cheaply as part of a shop years ago and love it, since it's the same exact profile as my macbook and I have a 2-sided case that holds the 2 of them perfectly. It' also very lightweight.
I have an iPhone for quick scans if needed, but it's really hard to get a clean copy of the receipts with the phone, while the flatbed scanner does it quick ad easy, and drops the files on my desktop.
As a guy, I fold all of my receipts and put them in my billfold. Trying to photograph a dozen receipts at the end of the day that all look like an accordion is frustrating...