The app-based service previously levied a 50p surcharge on debit and credit card payments.
From Saturday, a ban on all surcharges levied by companies on customers who pay with debit or credit cards comes into effect.
Businesses usually say the surcharge is to cover the cost of processing a card payment.
The change to Just Eat's billing, which took effect on January 8, has drawn criticism from customers, with one writing: "@JustEatUK 50p "service charge" are you just blatantly trying to get rid of your customer base? Awful."
Just Eat said it had already been reviewing its charges.
A spokeswoman said: "We were already reviewing our approach to charging for the services we provide to customers on behalf of our restaurants.
"As of 8 January 2018 we have made a change to the way restaurants are charged to process Just Eat orders - a 50p service charge will be implemented for all orders.
"Previously only customers who paid online were charged - we don't think it's fair for online payment customers to shoulder the costs associated with cash orders too, which is why we're introducing a charge applied equally across our customer base.
"The 50p charge simply means that along with our restaurant partners, we can continue to deliver the best possible takeaway experience, and applying the charge equally across the customer base, ensures fairness for all."
Just Eat jumped into the top flight of the FTSE Index in November.
The firm has seen shares jump 37% over the past year, with relentless revenue growth and a string of deals keeping its stock in demand.
Investor appetite for the company has helped push its stock market value beyond supermarket giant Sainsbury's.