Are you required to use the tax tables or the tax rate schedules or does it matter for 2015?

For the 2015 tax year, you are not required to use the tax tables or the tax rate schedules; either method can be used to calculate your tax liability. The choice often depends on your taxable income and personal preference. Generally, using the tax tables is simpler for lower-income individuals, while the tax rate schedules may be more suitable for higher incomes. Ultimately, both methods will yield the same tax amount if applied correctly.