He can look up near the top half of his Form 1040 below his name and address---there is a box that would be checked if he said he could be claimed as a dependent.
If you child can be claimed as your dependent and did not check this box, then you will not be able toe-file. Your return claiming him will be rejected and you will have to print, sign and mail your own return.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
