USCIS recently released a news alert that changes the filing procedures for U.S. petitioners residing abroad who wish to file for their immediate relatives. As of August 15, 2011, U.S. citizen petitioners who want to file a Petition for Alien Relative for their spouses or other family members MUST file their forms with the Chicago Lockbox Facility. In the past and until August 15, 2011, some petitioners residing abroad were able to file their immediate relative petitions directly with their U.S. Embassy via the Department of State at that U.S. Embassy. Filing directly with U.S. Embassies has generally been a faster way to approve visa petitions.
As of August 15, 2011, USCIS has centralized the filing location of the Immediate Relative Petitions to the Chicago Lockbox address, which can be found on the USCIS website.
There is an exception to this change, which is that if there is an international USCIS office having jurisdiction over the area where a petitioner lives, then those petitioners can continue to file their Immediate Relative Petitions with the international USCIS office.