Employers failing to provide tax exemptions and reliefs to employees during payroll deductions can result in employees being owed tax refunds. When filing individual tax returns, if an employee's actual tax liability is less than taxes paid, they are due a refund. Common reasons for refunds include employers not granting disability exemptions, insurance reliefs, mortgage interest deductions, or monthly personal reliefs. To apply for a refund, individuals log into the iTax portal and submit a claim along with required documents like deduction cards or certificates. Refunds are then analyzed and paid out once approved.