Supplemental Information for Spouse Beneficiary (Form I-130A) and Petition for Alien Relative (Form I-130) must be submitted together to U.S. Citizenship and Immigration Services, which means that a person who files marriage-based I-130 petition (petitioner) should also submit Form I-130A on behalf of a spouse.
It is a beneficiary (spouse) who should prepare Form I-130A. If he/she is present in the USA, his/her signature is required. If a beneficiary is abroad, he/she must fill in this form, but signature is not required.
Only marriage-based process of getting a green card needs a supporting Form I-130A. There is no need to attach it to Form I-130 for other types of family relationships (parents, kids, brothers/sisters).
November 9, 2019