This tip sheet will help you complete Form I864, Affidavit of Support Under Section 864A of the INA. Detailed Instructions for Affidavit.The petitioner in question must fill out Form I-864 Affidavit of Support when petitioning and sponsoring an immigrant. Form I864 must be submitted within one year of the sponsor's signature. If submitted after a year, a new I-864 form will be required. This tip sheet will help you complete Form I864EZ, Affidavit of Support Under Section 864A of the INA. Detailed Instructions for Filing. A letter of invitation or Affidavit of Support is not needed to apply for a nonimmigrant tourist visa. The person who is petitioning on behalf of the immigrant visitor fills out Form I-134. The petitioning sponsor is the relative who filed the immigrant visa petition on behalf of the intending immigrant.