Note that the offices of Thai Immigration in Bangkok located in Chaengwattana is where you need to go for a visa extension or renewal. You can also do your 90 day reporting at their offices on Chaengwattana road. This is a very busy immigration office so it is best to go early.
On average your visa extension can take between 4-6 hours to complete on an average day and your 90 day reporting will take about 1 hour to complete on average. Traffic on Chaengwattana road is a nightmare so don’t go late as the road gets bumper to bumper traffic very early. You can extend your tourist visa at their offices or you can also extend your Thai marriage visa or Thai retirement visa at their offices. This process takes about 3 weeks to complete if you have all your documents completed.
Below are the contact details for Thai immigration in Bangkok.
Thai Immigration Bangkok
The Government Complex
Tel: 0 2141 9953
Fax: 0 2143 8333
Opening Hours: Mon-Fri 08:30–16:30, Lunchbreak: 12:00–13:00
How to get there: By train to Laksi train station. Minivan to Pakkret.