Do I need certified marriage papers to apply for a Family Visa in Thailand with a European Union marriage?

The European Union is not a country 😕 The marriage was done in a specific country and it might need to be certified by the embassy of that country, then translated into thai, then stamped by the Ministry of Foreign Affairs office here in thailand.

Talk to your husbands employer to see if they are familiar with the process for you to get a Non-O 90 day visa issued based on marriage to a foreigner who legally works here.

If they are not, you and your husband need to go to your immigration office and talk to them about the steps in the process of first getting the 90 day Non-O visa under the "trailing spouse" clause and then the year extension that matches your husbands Non-B extension.