Source: Federal Trade Commission: Consumer Information
If you used the IRS’s non-filers tool before May 17 and claimed at least one qualifying child, the IRS mistakenly failed to send you $500 per qualifying child.
To correct this, the IRS is sending money to those people who were affected. (If you used the non-filers tool after May 17 and claimed at least one qualifying child, your stimulus payment did include $500 per qualifying child.)
You don’t need to do anything to get your money. The IRS began making direct deposits on August 5, 2020 and mailing checks and debit cards on August 7, 2020. You can check the status of your payment at irs.gov/coronavirus/get-my-payment.
The IRS won’t contact you about your payment. If someone does, it could be scam. Get the FTC’s latest information about Coronavirus scams at ftc.gov/coronavirus/scams.