Does TradeZero America charge an inactivity fee?

No. TradeZero does not charge an inactivity fee.

However:

• Accounts with a balance under $100 may be subject to a $5 quarterly Unqualified Account Fee
  

Important:

• To maintain access to the trading platform, your account must have at least $250 in equity
• To restore access, your account must be funded to at least $2,500