If client was in Texas and the check was in California, I don't think it was unreasonable that he didn't go and pick up this check. Check the postmark date on the envelope it came in (if that is still possible). It may not have been mailed until 2008 based on when your client received it. I would say it is 2008 income, but if a 1099 does say 2007, it may not be worth fighting over.