Under the new procedures implemented the National Visa Center (NVC) collects immigrant visa fee, affidavit of support fee and application forms (DS 230 Part I and II), Affidavit of Support forms for US Embassies and US Consulates around the world. The NVC is the main office of all U. S Consulates around the world located at Portsmouth, NH in United States. This office processes all immigrant visa applications once the I-130 petitions are approved by the U. S Immigration (USCIS) and forwarded the approved file to NVC. The NVC comes under the Department of State while the USCIS comes under the Department of Homeland Security. Thus both the USCIS and NVC are different agencies under two different departments of the Federal government. Both follow the Immigration and Nationality Act (INA) to adjudicate the cases before them. Both agencies have their own rules mostly similar to adjudicate the cases under the INA. Both agencies are authorized to make their own decisions regarding each petitions like the USCIS has authority whether to approve or not to approve or revoke the petitions approved and NVC has the authority to decided whether a person is eligible for visa or not or to send an approved petition back to USCIS for revocation or for further review. This is done in cases where fraud is involved by the petitioner or the applicants for visas at the consulates based on the information collected through interview and other sources. Hence it is important that filing of I-130 petitions for spouses and other relatives must be accompanied by copies of genuine documents mandated by the rules issued by the government authority. If primary documents like birth certificates, marriage certificates and death certificates are not available, the USCIS may accept secondary documents. If you are not sure what kind of documents are needed with the I-130 petition, you should contact an immigration attorney who has experience of several years of filing similar petitions especially for the applicants of your country.