IT declaration is a yearly process wherein employees can declare their IT declaration to save tax deductions for the financial year. Generally, declarations are done at the beginning of the financial year, when a new employee joins, salary structure changes, and when there is a request from an employee to change investment details. Income Tax declaration helps you to estimate the employee's Income Tax.
Proof of investment is a yearly process, where an employee must provide necessary documents as proof of their investments at the end of the financial year. The taxable income and tax deductions will be re-computed based on the submitted POI documents.