What is a common requirement for all filing statuses?

The correct answer, which is that all filing statuses require complying with residency tests, reflects the importance of establishing a taxpayer's residency status to determine their tax obligations. Residency tests help ascertain whether an individual qualifies to file as a resident or a non-resident for tax purposes, impacting the rates and deductions they may be eligible for.

While other factors play a role in determining filing status, residency tests are foundational because they help define an individual's tax responsibilities based on where they are considered a resident for tax purposes. This can involve factors such as physical presence in a location or connections to that location, which are critical for appropriate tax filing.

Meeting minimum income levels is not a universal requirement for all filing statuses, as some individuals may not owe any taxes regardless of their income levels based on their particular situation. Having a valid social security number is crucial for many aspects of tax filing, but not all individuals in every filing category are required to have one, particularly in the case of certain non-resident filers or individuals without a number due to specific circumstances. Certifying the tax year is relevant for tax filings but does not apply across all filing statuses. Therefore, residency tests emerge as the common requirement across various filing categories.