If you are in Nong Khai or entering Thailand from Laos then you can find Thai immigration in Nong Khai. This immigration office can extend your tourist visa for 30 days and you can also extend your marriage and retirement visa at this office.
If you need more information and help then contact Thai immigration in Nong Khai for more information. Most people arriving from the Thai embassy in Laos normally use this office when they want to extend their visa while in the area. Note that the train station is not very far from immigration in Nong Khai.
Thai Immigration in Nong Khai
Opening Hours: 8:30am-4:30pm Monday to Friday
Service Area: Nong Khai province