Form I-824 is the application to receive a duplicate approval notice, Form I-797. If you have filed an immigrant petition or application that was approved but you never received an Approval Notice or if the Approval Notice was lost, then you can file Form I-824 to receive a new one.
Form I-824 is also used for Follow to Join purposes.
Duplicate Approval Notice
It is important to have an approval notice as it may be needed for further action on an application, to prove to a USCIS officer or other government official that your nonimmigrant status is in the process of being adjusted, and to document your application process. Therefore, if you have lost your approval notice you should immediately request a new one using Form I-824.
How to Request a Missing or Lost I-797 Approval Notice Form:
The I-797 is titled Notice of Action. It is issued when an immigration application or petition is approved.
Filing Form I-824 will only get you a duplicate approval notice with the information listed on the original Form I-797. A replacement employment authorization card, Form I-94, Permanent Resident Card, or any other USCIS authorization document will not accompany the duplicate approval notice.
What is follow to join?
Spouses and children of United States permanent residents may obtain visas to the United States through the Follow to Join process. You may use Follow to Join if the principal applicant (U.S. permanent resident) has established permanent residence through the Employment-based category, the Family-preference category, the Green Card Lottery, or was issued a K or V visa. The benefit of the Follow to Join process is that a separate I -130 does not need to be filed for the applicant family members.
What is Form I-797?
Form I-797 is the Notice of Action. It is issued when an immigration application or petition is approved.
Lost Naturalization Certificate?
If you have lost your Naturalization Certificate or it has incorrect information, been damaged, or stolen, then you can file for a replacement certificate using Form N-565.