Should we amend NJ State resident & NY State Non resident return, if amended Federal Return is filed to add dependent for "Credit for Other dependents" deduction in 2018?

[is_rg]

I want to amend my 2018 federal return as I want to apply ITIN (Form W7) for my dependent after I filed my original return for 2018 to claim "Credit for Other dependents" as my dependent is not eligible for SSN. If I amend, the federal return for this purpose, am I required to amend NJ State Resident return and NY State non resident return as well?

Because generally the notion is if you amend federal return, you must amend State returns.

[Critter · Accepted solution]

I highly suggest that once you get the ITIN you amend the state returns as well to see if there is any changes. 

[is_rg]

ITIN has no impact on State Tax returns. My question is more inclined towards compliance to returns. Is it mandatory to amend State tax returns if an amendment in Federal return has no impact on State taxes?

[Critter]

Ok ... without the ITIN you could not file the state return claiming that dependent  ... so if you add a dependent to the federal you will also want to add it to the state ... so it could make a difference which is why I suggested you try and see.