Is zakat obligatory on the money remaining from a salary after a full year has passed and it has reached the nisab, knowing that zakat on salaries is paid annually to the authorities?

The monthly salary is not subject to zakat unless a full year (hawl) has passed over it, and it reaches the minimum threshold (nisab) by itself or when combined with other wealth (such as gold, silver, trade goods, or paper currency). One-quarter of a tenth (2.5%) is to be given out with the intention. It is permissible to pay zakat in advance after the wealth has reached the nisab, but it is not valid to pay it in advance before it reaches the nisab.