Sez Unit ko sale hamesha export sale hoti hai (unless goods is exempted) Toh agar supplier ney LUT nahi file kiya hai to Bill per IGST charge Karega , haan Sez unit supplier ko IGST amount jo bill per charge kiya hai uski payment nahi karega , supplier ko woh IGST jama karana hai , aur phir uska refund apply kar sakta hai