2003 Corolla S - Fuel Gauge Stuck At Half Tank

[teamstites]

Hi,
I just bought a used 2003 Corolla S from a private party. The car has 107,000 miles. Unbeknownst to me when I bought the vehicle 2 days ago the fuel gauge never moved off a half tank. So I put $20 worth of gas in it today and it still didnt move. When I turn the car off it goes down to empty and then when I turn the car on it only goes to half way.
What could possibly be the issue? And what would it take to fix it.
Thanks

 

[Scout706]

A few attempts

You have ruled out a stuck gauge, try filling the tank up and running it down as far as reasonable, using the trip odometer and estimated fuel economy. Filling it up might loosen the float.