Your application or petition was approved, but if you lost the approval notice or if you never received the original notice of approval, you can request a duplicate notice of approval (I797).

e.g., if Form I-130, a petition to bring a relative to live in the United States was approved but you lost the original notice, you may request a duplicate notice of approval.
Also, many times, an approved petition for a visitor visa extension is lost and it is now required to apply for a visitor visa again, if the person stayed beyond original I-94 date stamp during previous visit.

In order to receive a duplicate approval notice, you must file Form I-824 while the original application or petition is still in effect.

Please note that the duplicate notice will contain only the information listed on the original Form I-797, Notice of Action. A replacement employment card, Form I-94 or any other USCIS authorization document will not accompany the duplicate approval notice.

You may not file this form to request a duplicate notice for an application or petition that is pending or has been denied or a duplicate approval notice naming a spouse or children accompanying or following-to-join the principal beneficiary on an approved immigration petition.

• Form I-824, Application for Action on an Approved Application or Petition
  
  
• Check Box A in the application for reason for filing Form I824 as this form is used for several other purposes.
  
  
• Application fee must be sent with the application.
  There is no biometric fee.
  
  Fee details
  
  
• Evidence
  Attach copies, showing the front and back of the following documents, if available.
  • A copy of the original petition or application.
    
    
  • A copy of the Form I-797, Notice of Action, for the original petition or application.
    
    
  Do not send original documents unless instructed to do so.

You must file Form I-824 along with required documents at the USCIS office that approved your original application or petition. This could be either a USCIS Service Center or local USCIS office.