I'm a bit annoyed at myself, to be honest Malone. I've got the phone app version of both Chambers dictionary and thesaurus, but only looked up 'Income' on the Free Online Dictionary. When you told me it was in Chambers I checked and.....lo and behold, there it was!
I just finished the crossword about 10 minutes ago, there's a few I can't parse but I've managed to do all the shading etc so pretty pleased. It's amazing how the setter managed to construct this - not only are all the US states in the grid (minus one, but that's intentional), but they're all in their relative geographical positions.