Hi Paul,

....=SUMPRODUCT(--(Sheet2!A2:K10001=A7),--(Sheet1!H2:H10001),Sheet2!K2:K10001)

Watch 2 things ...
1. Range criteria of column H should be of the same size as other
ranges ...
2. When referring to non numeric columns, use the unary operator --

HTH
Cheers
Carim