Self-employed delivery driver lives in Vancouver WA and as part of his work delivers goods/food/Amazon between WA and OR. Only one of his 1099's is from a company registered in OR and states OR income. All others are from WA companies and no state income shown. Does he need to split his income between the two states based on the miles driven? Or it is split based on the location of the company that issued 1099? Thank you!
