I accidentally sent in more money than I owed. Can I get it back?

[Tmil043]

I finally received notice they'll be giving my overpayment back!

Would I be eligible for interest, and if so, how would I initiate that? 

Overpayment was made April 15 2021 for the 2020 tax year - letter date is listed as Jan 19, 2023. 

[DoninGA]

@Tmil043 The IRS will automatically send you an interest payment for the delayed tax refund.  You cannot initiate that process.

Note the interest paid is taxable on your tax return for the year the interest was paid.

[Critter-3]

Note the eligible  interest is included in the payment they send ... it is not a separate payment.

[Phtmzephyr]

And what about the following case?

I overpaid due to a software error (basically paid twice) for 2020 tax year. The IRS sent me a letter a year ago stating they acknowledged the overpayment and would be sending me a refund within two weeks...

It has been a year since then and basically two years since the overpayment and I STILL don't have my money. Calling the IRS is a waste of time. I have spent 20 hours total on the phone and never spoken to a single person.

I am filing my taxes for 2022. How can I get this money back along with the return I have coming this year???

[Critter-3]

I am filing my taxes for 2022. How can I get this money back along with the return I have coming this year???

You can't ... but you can contact the Taxpayer Advocate in your state for assistance.  Did you look at the tax account or return transcript in your account  at the IRS?  That may shed some light on the situation. 

https://www.irs.gov/payments/your-online-account

See this IRS website for Taxpayer Advocate in your area and a toll free number - http://www.irs.gov/Advocate/Local-Taxpayer-Advocate