Logging website service fees

Logging website service fees

Hello,
I do a lot of freelance work on sites like Upwork and Wyzant and others and those companies take a small cut from what I pay or what I earn and I am wondering what is the correct way to log this in my books.

For example if I charge $55 per hour and the site pays me 75% of what I earned, I get paid $41.25, and the $13.75 goes to the site.

Thanks