In simple words Assessee means a person who is liable to pay tax or any other sum of money under income tax.
As per Section 2(7) of Income Tax Act, 1961 assessee means:
Person by whom any Tax or any other sum of money is payable under this Act.
Any person who is entitled to refund of Tax under this Act.
Any person against whom some proceedings under this Act are going on. It is immaterial whether any Tax or other amount is payable by him or not
A person may not be liable only for his own income or loss but also on the income or loss of other persons e.g. Legal Representative in case of death of a person, Agent of a Non-Resident etc. [Deemed Assessee or Representative Assessee]
A Person who is deemed to be an assessee in default. Under Income Tax a person is deemed to be an assessee-in-default if he fails to fulfill his statutory obligations. For example failure to deduct TDS.
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