I have a fortnite code worth around $300. How does selling it work? What stops the buyer from claiming the code never worked?
You can use the following article to see how to sell a game code and the guidelines to avoid issues:
Here are the Restrictions and Requirements for selling this type of item (listed inside the article above):
So keep in mind to maintain the proof of purchase and other types of information that proves the code was working before the buyer received the code.