Every trainer that you defeat in Pokemon Sun and Moon will give you money for your victory. However, there is a way in the game to increase the money you get per battle – and that is through the Amulet Coin.
About the Amulet Coin
The Amulet Coin is an item that a Pokemon holds that doubles the money given during battles with trainers.
The effect of the item does not disappear even if the Pokemon holding it faints or gets switched as long as the Pokemon takes a part in a battle. Also, the item will still work even if it is stolen or knocked off.
This item is very important since the number of times you can battle against a trainer is limited when progressing through the main story.
Where to Find it
It can be found in Paniola Ranch on Akala Island, the second island that you will explore in the game. Luckily, it isn’t hard to find. Find the red truck near the Pokemon Nursery in Paniola Ranch. The item is right behind it.
For more information on other items you can find in Akala Island, visit Samurai Gamers’ Akala Island walkthrough.
What if you accidentally sold it?
Then you’re fucked getting money the long way, unless if you link trade and happen to run across someone who has an amulet coin on their Pokémon in which you can trade from.