You put that in the memo field on your check.
No, the IRS does not acknowledge the receipt of an amended return. The only proof of mailing that the IRS accepts is if you mail certified (or registered) mail with return receipt or other tracking that proves delivery.
You can check the status of the amended return here, but allow 3 weeks after mailing.
https://www.irs.gov/filing/individuals/amended-returns-form-1040-x-/wheres-my-amended-return-1
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
