Student or Learner
What is the difference between cough up and fork out in term of paying unwillingly
"To fork over" is also common. The three are commonly used in the USA. I see no difference. Be aware that they are often used humorously without any intention of insulting or offending.
Jack, you owe me a dollar for the coffee. Fork it over.
I had to cough up $100 to pay for the mechanical work on my car.
Jill, how much did you fork out for that coat?