The sentence "There is no need to pay" is correct and can be used in written English. You can use this sentence when trying to convey that something does not require payment. For example, "The library offers free books, so there is no need to pay for them".

One simple way to say no need to pay is by saying ‘Don’t worry about the bill I’ll handle it’. This is the most straightforward way to inform a person you are handling their bills. It is a direct way to help the other person without them asking. It is modest and doesn’t portray you as being obnoxious or inconsiderate.