There could be any number of reasons that a particular taxpayer might not qualify for the California Earned Income Tax Credit.
Did your son possibly have investment income of more than $4,053 during the year? That would disqualify him.
Please see the Specific Instructions in 2021 Instructions for Form FTB 3514 California Earned Income Tax CreditRevised: 02/2022 for specific requirements.
You can also use the EITC Calculator on the California Earned Income Tax Credit and Young Child Tax Credit page to verify whether or not your son qualifies and, if so, for how much.
