Will social security in the form of wages send unit to do so you don't have to pay social security?

Units will be distributed to employees' social security in the form of salary do you don't have to pay social security? Unit of choose and employ persons must pay social insurance for its staff and workers, but in real life, a lot of conventions and unit, not pay social security, and social security in the form of wages to labourers. Surface, workers in addition to not deduct from salary individual should pay part, can also extra "income", the unit also removes protect capture "trouble" for employees. But this to work...