Tax Year in Income Tax: Meaning, Example, Start and End Date

The new Income Tax Act 2025 replaces both the “Financial Year (FY)” and “Assessment Year (AY)” with a single, unified concept called the “Tax Year”, which is a straightforward 12 month period from April to March, during which income will be earned and for which taxes are filed in the following tax year. This concept is effective from 01st April, 2026.

What is a Tax Year in Income Tax?

Tax year as per the Income Tax Act 2025 will replace the existing concept of Financial Year and Assessment Year. A Tax Year is a 12 month period that begins on the 1st of April and ends on 31st March of the following year. However, for newly established business and profession, the tax year starts from the date of establishment. 

For example, Tax Year 2026-27 is a 12 month period which starts from 1st April 2026 and ends on 31st Match 2027. 

Current Income Tax Law: Which Years are relevant?

In the current Income Tax Law, the concept of Previous year and Assessment year is used. 

• Previous Year: Simply speaking, it is the year in which the income is earned. It can be less than 12 months in case the business is newly set up or the source of income is new. In those cases, the previous year is from the date of beginning of the new business/income source to March 31st.
• Assessment Year: Simply speaking, it is the year in which the tax is paid for income earned. It is the year next to previous year. In assessment year, the income earned in previous year considered for tax purposes and tax is paid, if applicable.

This dual reference to years created a lot of confusion among tax-payers. Therefore, these concepts were revamped and the concept of “Tax Year” was introduced.

How do we refer to Previous Year and Assessment Year in the New Bill? 

• Wherever reference needs to be made to Assessment Year in the new bill, the terminology has been changed to “Subsequent Tax Year”. For instance, in section 263 talks about filing of income tax returns. 
• We all know that the filing of returns happen in assessment year (which is next to previous year). Instead of referring to assessment year, we say it as “ Financial Year succeeding to relevant Tax Year”.

Can a Tax Year be less than 12 months?

Yes! Very much. As previously mentioned, a tax year can be less than 12 months in the following cases:

• A new business or profession is set up in the middle of the financial year.
• A new source of income set up in the middle of the financial year.

For example, a new business is set up on 01st June 2026, the tax year in this case would be from 01st June 2026 to 31st March 2027. Not 1st April to 31st March. 

Comparison: Tax Year v/s Financial Year v/s Assessment Year

The comparison of tax year under the new Income Tax Bill, 2025 and Financial year and Assessment year is as follows:

Will this Impact my Tax Filing?

• The removal of the concept of financial year and assessment year simplifies the tax process, giving taxpayers a better overview and lesser confusion.
• It tends to simplify the operation of the tax authorities additionally by minimizing amounts of disparities and misinterpretations concerning assessment periods and the financial periods.
• Therefore we can conclude that introduction of the concept of Tax Year does not change the dates of filing return, or the manner of filing. It has resulted in nothing but simplification of law and make it more accessible to public at large.

Final Word

The concept of tax year removes significant hurdles in understanding the tax laws, its applicability, relevant income and deductions. This is one of the most crucial changes made by the government, toward the goal of simplified tax laws and compliance.