I don’t usually file taxes, what will I need to submit to sign up for the Child Tax Credit?

An email address, ID, proof of income and/or benefits, and your child's Social Security Number.

Children claimed for the Child Tax Credit must have a valid Social security number (SSN), however the tax filer (a parent, grandparent, or guardian) can have either a SSN or an Individual Taxpayer Identification Number (ITIN).