Hi Marco. To be sure and have no delays whilst applying go to the immigration office you will use in advance and get a list of what they need for the Marriage Visa application. I applied yesterday in Khon Kaen. I had there list with me, the orginals documents plus 3 copies of everything they requested. They were happy i had followed there request and i was on my way home within 50 minutes. Its worth the trip to get the info first before applying.