It is the responsibility of the employer to deduct income tax from the salary of employees monthly on the proportionate basis and deposit before the due date ( Monthly) as prescribed and report same to Income Tax Department (quarterly as well as annually). The aggregate tax calculated on the estimated projected income will be deducted proportionately in 12 months, thus the assessment needs to be done on at the start of the year.
Therefore, all employees are requested to declare their proposed investments for the year, so that proportionate income tax could be calculated & systematic deduction from the salary can be started early.
Form 12BB applies to all salaried taxpayers. Using Form 12BB, an employee has to declare the investments that they have made during the year. Documentary evidence of these investments and expenses have to be provided at the end of the financial year as well.
Please see the blog given below to know in detail:https://cleartax.in/s/guide-to-form-12bb