Marriage to a U.S. citizen or lawful permanent resident does not, despite popular myth, automatically guarantee a marriage visa (U.S. lawful permanent residence or a green card) to the immigrant. Due to the potential for marriage fraud, U.S. Citizenship and Immigration Services (USCIS) as well as the U.S. State Department and consulates, carefully scrutinize all marriage visa applications.
Assuming your case is the real thing, not a sham to get a green card, here are some common mistakes to avoid, any of which could result in your application being denied.
For purpose of immigration, you must be legally married. That usually means with a governmentally recognized service or ceremony. Read Can You Get a Green Card By Common-Law Marriage? for the few exceptions.
You must be legally married under the laws and customs of the state or country in which you were married. If, for example, your state or country prohibits marriage between certain blood relations or between an underage person and another, you'll need to make sure your marriage does not violate these rules.
You will need to submit evidence of your valid marriage along with the initial petition (Form I-130) that the U.S. petitioner must prepare and submit. The best evidence of marriage is your marriage certificate, issued by a government agency. A church document or other unofficial certificate will not be accepted unless you can show that your marriage is nevertheless valid in the place it occurred and the original certificate is unavailable.
Also, you must not still be married to someone else. If you were previously married, you will have to provide proof that the marriage has ended, for example by submitting death or divorce certificates to USCIS. Failure to include such proof will, at a minimum, result in your green card application being delayed while USCIS requests this information from you.
Many green-card seekers living in the U.S. hope to apply for their green card without leaving the country for what's called consular processing, including an interview at a U.S. embassy or consulate. However, if the person's latest entry to the U.S. was unlawful, this is a problem. The person is not eligible to adjust status, or turn the green card application in to USCIS.
(The adjustment of status procedure is mostly limited to people who entered the U.S. legally.) In fact, submitting an adjustment of status application could result in the person being placed in removal proceedings.
Here's information on adjusting status after marriage.
The "normal" way that the U.S. immigration authorities expect spouses to apply for a marriage visa is for the U.S. petitioner to start the process by filing a Form I-130, after which the immigrant communicates with an overseas U.S. consulate and attends an interview there. However, this can take months, during which time the U.S. petitioner is normally living in the U.S. while the immigrant lives in another country.
Out of frustration, some immigrants have tried entering the U.S. on a tourist visa and then adjusting status. Technically, this combination is possible for some people. You might even have friends who have done this. However, there's a catch. In order for this strategy to work, immigrants need to prove that they didn't misuse the tourist visa (commit visa fraud) by claiming to be a mere visitor, when in fact intending to stay and get a U.S. green card.
If the immigrant simply came as a tourist and later met the spouse-to-be or decided to married, that's normally okay. The longer the time period between the tourist visa entry and the submission of the green card application, the more chance USCIS will approve it.
But if the immigrant enters the U.S. as a supposed tourist and then, within a matter of weeks or a couple months, submits a green card application based on marriage, expect to be questioned about the immigrant's intentions upon entry, and then for the case to possibly be denied U.S. permanent residence based on visa fraud (a ground of inadmissibility).
U.S. immigration laws prohibit the issuance of an immigrant visa to any person who is likely to become a public charge (receive need-based public assistance or welfare). The U.S. citizen or lawful permanent resident spouse must file an Affidavit of Support on Form I-864 to prove that he or she will provide the immigrant any necessary financial support for a period of years to avoid this prospect.
Failure to file this Affidavit, or to show sufficient financial resources to maintain the immigrant and the sponsor's household at a level that's at least 125% of the U.S. Poverty Guidelines (as shown on Form I-864P; the amounts change every year), will result in your application being denied.
Also, even showing sufficient income on the Form I-864 might not be enough if other factors suggest a likely need for government assistance.
You must fully and properly complete the various application forms. Do not leave any questions unanswered. If a question is not applicable to you, write "N/A" for "not applicable." Make sure that you have entered your personal information correctly. Your name, last name, date of birth, place of birth, country of birth, and so on must match with the details on your passport.
The photos you attach need to meet the Department of State's specifications for size, color, and so on. Do not attempt to take these yourselves; go to a professional who provides this service.
Make sure that you submit the completed application form along with the necessary documents to the right USCIS office. Sending it to the wrong USCIS office will delay your application. You will also need to attach the correct fee. Read the instructions on the USCIS website carefully.
If you are submitting any foreign document in support of your application, you must submit a certified English translation of the document. This must be a full, word-for-word translation, not a summary.
For any questions on the above, see an immigration attorney.