The A$/$P Term $2$ N $30$ normally means:

There is a $2\%$ discount for early payment and the invoice is due on the $30$ th of this month

There is a $2\%$ discount for early payment and the invoice is due in $30$ days

There is a $2\%$ discount for early payment and the invoice is due on the $30$ th of next month

There is a $2\%$ discount if the invoice is paid in $30$ days