Ok ... there is no reason to make that correction ... the bottom line on the 2018 return is what it is and paying it would not change that fact.
For instance, on your Dec 2018 phone bill they send you ... it has a balance due on it. That bill will never show it was paid but it will show paid on the next bill in Jan 2019 which is like showing the 2018 payment on the 2019 return ... but in the case of a fed balance due it will only show on the state return IF the state requires it and most do not.
