Japan's tax-filing season opened Monday with more than 500 local tax offices nationwide accepting income tax returns, the National Tax Agency said.

The agency has requested that those who need to file income tax returns do so early. Returns can also be filed by mail. The deadline is March 15.

The self-employed, including shop owners, doctors and lawyers, are among those required to file income tax returns, along with employees who receive salaries from more than one source.

Salaried workers with annual incomes exceeding 20 million yen as well as salaried workers with additional income exceeding 200,000 yen a year are also required to file income tax returns.

The tax-filing season usually starts Feb. 16, but since that day fell on Saturday this year, Monday became the season's first day.