Mexican naturalization (naturalization letter)This is filed with the Ministry of Foreign Affairs, not with the INM, and that confusion costs many people time. The residency period you need depends on your case: five years in general, or two if you're married to a Mexican, have Mexican children, or are of Ibero-American origin. Two things surprise almost everyone: your absences from the country are counted and must not exceed 180 days in…Confirm your category — you may wait less than you thinkThe residency period depends on your case. Generally five years, but it drops to two if you're married to a Mexican, have Mexican children, or are of Ibero-American origin. Many people count five years without knowing their case allowed two. Each category requires different documents, so…Count your absences: the limit is 180 daysOn the general route, your absences from the country must not exceed 180 days in total during the residency period being assessed. This is stricter than most people expect. Before applying, do the math using your entry and exit stamps.Request your entry and exit report from INM — do this firstThis document is issued by INM and is what proves you have actually lived in Mexico. It's one of the slowest to arrive and one the SRE reviews most carefully. Request it as soon as you decide to start, not at the end: it's the one that can delay everything else.Gather the rest of the fileYou need: your valid resident card (with enough validity left when you file), a valid passport, your birth certificate from your country of origin apostilled and translated by an authorized translator, non-criminal record certificates both federal AND local (many people bring only one), photos to…Complete the online pre-registration and choose a locationThe process begins with an online pre-registration where you choose the SRE office where you'll submit. Even if you file at a state office, all files are forwarded to the central office for resolution.Review the file twice before submittingThis step seems obvious and saves the most time. A high proportion of applications are returned for correctable paperwork errors, not for the merits of the case: a missing document, copy, or signature. Half an hour going through each document against the official checklist can save you months of…Take the exam and the Spanish interviewIf your documentation is correct, you move to the knowledge exam, prepared by the Instituto Matías Romero: it covers history, culture, and civics — government structure, the three branches, human rights, national holidays. The SRE publishes a study guide with topics and sample questions; get it…Receive your naturalization letterWith a favorable resolution you receive your naturalization letter, the document proving your Mexican nationality. With it you can obtain your CURP as a Mexican, your Mexican passport, and your voter ID. Before reaching this point, check what your country of origin says about dual nationality: some…