Once the NVC receives your approved I-129F petition from the USCIS, they will send your case on to the US Embassy’s Immigrant Visa (IV) unit in Bangkok. They will also issue the Thai applicant’s case number for correspondence with the US Embassy. It takes the NVC approximately three to four weeks to process the petition. Once the embassy’s IV unit has received your file, they will email you with instructions (known as Packet 3) on how to prepare the required documents for the interview.