What does it mean to go mahjong?

Going mahjong means declaring a winning hand. When a player draws or claims a tile that completes their hand and meets the minimum fan requirement, they announce "mahjong" (or "hu" in Mandarin) to signal their win. The hand is then laid face-up on the table for all players to verify the fan count and calculate payments. Declaring a false win carries penalties, so players must be certain before announcing.