How to know when IRS & CA State USPS mailed returns have been Accepted or Input to Fed & State systems?

We are told that we need proof of 'Filing' by my spouse's government employer.

I am not asking about the timing of the refunds due for ALL the state and federal returns sent in.

 

How long before 2020 and 2021 federal returns, mailed 12-31-24 and 'delivered' to the IRS 1-6-25 via certified mail, will show up on our IRS website account? I assume that is the only way to prove the IRS has theses older returns.

 

State '20, '21, '22, '23 and Federal '22 & '23 Tax returns were sent via USPS certified mail 1/14/25, so we will know when they are 'delivered' via the USPS tracking (probably 1/17/25). What is the soonest, after the State and Federal returns are known to have been 'delivered', would we expect to be able to find proof of filing from: 1) Wheres-My-Refund, 2) IRS2Go mobile app, 3) Our IRS website account?

 

The IRS.gov/wheres-my-refund site   gives options to search for '22, '23, '24 tax years.

The mobile app IRS2Go offers the same '22, '23, '24 tax years.

I did not check into options to learn of proof of filing for the state returns yet. Any help to understand when I might be able to see/ prove that my '20, '21, '22, & '23 California returns are officially 'Filed' would be appreciated.

 

We mailed the two oldest federal returns for 2020 and 2021 on 12-31-24. USPS certified mail tracking shows these were both delivered 1-6-25. Obviously, the two above inquiry methods will be of no use for these older returns.

 

Thanks for any info or experience you may have in when someone is able to see when the agencies acknowledge receipt/ filing of tax returns is appreciated.

Thank you,

Dave