Final answer:
The spouse aged 63 who earns $1,200 while married filing separately is likely not required to file a tax return as the income is below the standard deduction for that filing status, according to IRS guidelines for 2010. Additional details or changes in tax law may affect this, so consulting current IRS guidelines or a tax professional is recommended.
Step-by-step explanation:
The filing requirement for the spouse who is aged 63 and earning $1,200, while married filing separately, is determined by the Internal Revenue Service (IRS) guidelines. According to the IRS, the standard deduction for someone who is married filing separately is $5,350 for 2010. However, the filing requirement can vary based on factors such as age, income, and marital status. Since the spouse's income ($1,200) is significantly lower than the standard deduction, it is likely that the spouse is not required to file a tax return. However, if there are additional incomes, credits, or other factors to consider, the spouse may be required to file. In general, the IRS requires a return if the individual's gross income is at least as much as the standard deduction for their filing status.
It is also important to note that tax thresholds and deductions often change every year, so one should always consult the latest IRS guidelines or a tax professional for accurate advice for the current tax year.