Family name Promtas (Promtas 
) , globally, is a very rare cognomen. The last name Promtas is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Much less frequently, Promtas is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Promtas | Thailand |
Somsak, Susaraporn, Sopaporn, and Kanjanee