After you file

@xmasbaby0 - The 2nd stimulus is based on 2019 tax return only.  So if someone didn't file 2019, then the way to get the payment is obviously the 2020 tax return.  That means some will get different stimulus payments (the dollars figure per person aside) because the 1st one may have been based on 2018 income and dependents and the 2nd one would be based on 2019 income and dependents.

 

https://www.irs.gov/newsroom/treasury-and-irs-begin-delivering-second-round-of-economic-impact-payme...

 

Payments are automatic for eligible taxpayers

Payments are automatic for eligible taxpayers who filed a 2019 tax return, those who receive Social Security retirement, survivor or disability benefits (SSDI), Railroad Retirement benefits as well as Supplemental Security Income (SSI) and Veterans Affairs beneficiaries who didn’t file a tax return. Payments are also automatic for anyone who successfully registered for the first payment online at IRS.gov using the agency’s Non-Filers tool by November 21, 2020 or who submitted a simplified tax return that has been processed by the IRS.