You should carry extensive documentary evidence of the relationship between the petitioner and the primary beneficiary (in case of family based petition) and between the primary beneficiary and any derivative beneficiaries.

If you fail to do so, it could greatly delay your application while your application is investigated.

Some examples of such evidence are family and other photographs (old and recent) showing the parties together, letters, cards, correspondence, and telephone records.

You must be prepared to present the original of all civil documents that establish your claimed relationship to the petitioner.

• Spouses of U.S. Citizens (IR-1, CR-1, and K-3 Visas), spouses of Legal Permanent Residents (F-2A and V-1 Visas) and Spouses of Family Based Visa Applicants (F-3 and F-4 Visas):
  
  Primary: Marriage certificate and proof of prior marriage terminations
  
  Secondary: Wedding invitations, church certificates, wedding photographs or other reliable documents that show the required relationship. For proof of an ongoing relationship, submit evidence such as cards, letters, emails, photographs, phone records and other evidence that your relationship is continual.
  
  More information
  
  
• For Children (IR-2, IR-3, F-1, F-24, F-3 and K-4 Visas) and Parents (IR-5 visas) of U. S. Citizens, Children of Family Based Visa Applicants (F-3 and F-4 Visas) and Children of Fiancé(e) visa applicants (K-2 Visas):
  
  Primary: Old passports, birth registrations issued within one year of the birth.
  
  Secondary: Secondary school leaving certificates, old ration cards, old baptismal certificates, old family documents such as land transfers and wills, original wedding invitations, college degree certificates, mark sheets, property certificates, family photos or other reliable documents which show the required relationship.
  
  
• For the Brother or Sister of a U. S. Citizen (F-4 Visas):
  
  Primary: Old passports, birth registrations issued within one year of the birth.
  
  Secondary: Secondary school leaving certificates, old ration cards, old baptismal certificates, old family documents such as land transfers and wills, original wedding invitations, college degree certificates, mark sheets, property certificates, family photos or other reliable documents which show the required relationship.
  
  

Note: The documents of both the petitioner and beneficiary must show parent(s) name(s) to be considered in connection with the immigrant visa application.