How to entry this : $30,000 of notes payable are due for payment next year. ( since there is $28,700 cash on Trial Balance.)

The question is vague but it sounds like what you're getting at is that there is a long-term note payable and that $30,000 of that is due within the next year, making it a current portion.

Remember that anything to be paid within one year is current and anything in over a year is long-term. If you have a long-term note, chances are some portion of it is due during the next year -- i.e.you either have a payment due once a year, or monthly payments. The portion that is due during the next year is considered current, even though the note itself is long-term.

But since the loan is sitting in long-term liabilities, you have to pull that current portion out of there and move it to current. Whether an entry is required of you depends on what they want. (An entry isn't technically required because it's just a matter of how it's reported on the balance sheet. However, some texts have you do an entry, and when using software it becomes necessary just as a technicality of the software. The entry is literally taking it out of one and putting it into the other, trading liability for liability.)

The current portion will be called exactly that: Current Portion of Long-Term Debt, and generally the long-term portion will have something like "Less current portion" in parenthesis after it.