"You have nothing to worry about with that account." "You have nothing to worry about on that." "There's nothing to worry about on that account." "There's no need to worry about that account." Any place you don't use the word 'account' it has to be clear that the account is what you're talking about.

The phrase you have asked about its common and correct. However, if you are looking for some alternate ways to say it you could say... "You have no to reason to worry about....(insert the thing the person is worried about)." "There is no reason to be concerned on this point..."

I would not change it. It is a very common and standard phrase, it is used frequently.