Can my son be on the same DTV visa as my husband, or do we need to apply separately?

I believe you are referring to applying for your son as a dependent on your husband's DTV visa.

To clarify, your husband would first need to have his DTV visa approved. After that, you can apply for your son separately as a dependent. Please note that you will need to show the minimum financial requirement for each person (e.g., THB 500,000 x 2 = THB 1,000,000) for a period of 3 months.

If you are applying for both yourself and your son, the same process applies, and the additional financial requirement would total THB 1,500,000.