It is generally best to obtain your visa stamping at the US Embassy or Consulate serving your home country. However, if you must go for stamping at a Consulate that is not in your home country you must check local policy at your destination Consulate to ensure they will stamp your visa. US Consulates in Mexico, for instance, will not accept non-Mexico resident visa applicants who changed from one status to another while in the US or those who overstayed previously, among others.
What To Bring To the Consulate
The list of items you are required to take to the Consulate will slightly vary by Consulate. Always check the Consulate website for your destination Consulate before you attend your interview.
A general list of items is included below:
Valid Passport (must have 6 months validity remaining) and Previously Issued Passports, Appointment Confirmation Letter, DS Form 160 Confirmation Page with Barcode, Receipt as Proof of Visa Fee Payment (see your destination Consulate website for fee payment instructions), One Passport Photo 2"X2" on white background
Original I-797 Approval Notice, Complete Copy of the H Petition as filed along with signed and certified LCA (include any end-client contracts and end-client letters)
Original Degree Certificates, Transcripts and Mark Sheets, A Letter from your H Employer confirming that a position still exists for you and the details of the position.
Bring 1 extra copy of all of the above in the event the officer requests the same.
If You Had Prior Nonimmigrant Employment in the U.S.-Prove That You Maintained Status
If prior nonimmigrant employment in the US, bring proof that you maintained your status while in the US. For former F-1 Students, this includes all previous I-20s and W2s for EAD employment. For former H or L visa holders, bring your previous I-797s, evidence of your employment in the US, W-2s and pay slips. Prior H4 or L2 dependents, take evidence that your spouse maintained his/her status during your stay in the US as well as your marriage certificate.
How Long Will it Take After the Interview to Receive my Passport?
Once you attend the interview you can expect your passport to be returned in approximately 3-4 days. Therefore, it is recommended that you book your flight to the US only after you receive your passport with visa stamping.
Deal With Criminal Matters Before You Depart the U.S.
If you have any past criminal matters or have ever overstayed a visa in the US, seek counsel before you attend the interview. Criminal matters can greatly delay visa processing. If you have a past crime, you must acquire a certified final disposition for the case and ensure you take that with you to the Consulate.