[Grammar] overdraft in or on?

[Julie17]

Which preposition is correct?

a) This customer has an overdraft / credit balance of 500 pounds in her account.
b) This customer has an overdraft / credit balance of 500 pounds on her account.

 

[matt1979]

In the UK we'd always say 'in'.

I've £500 in my account.

 

[Matthew Wai]

matt1979, you have to state 'Not a teacher' in your answers unless you are a teacher.

Not a teacher.

 

[Julie17]

Is it the same if you leave out 'of 500 pounds'?
Would it be acceptable in American English?