For the average individual, trying to get tax related questions answered by the Internal Revenue Service is too difficult. Here are the top 10 questions taxpayers have regarding the IRS and filing taxes:

1. Can a person receive a tax refund if they are currently in a payment plan for prior year’s federal taxes?
As a condition of your agreement, any refund due you in a future year will be applied against the amount you owe.

Continue making your installment agreement payments as scheduled because your refund is not considered as a substitute for your regular payment due.
You may not get all of your refund if you owe certain past-due amounts, such as federal tax, state tax, a student loan, or child support.
IRS will automatically apply the refund to the taxes owed

2. What is a split refund?
A split refund lets you divide your refund, in any proportion you want, and direct deposit the funds in up to three different accounts with U.S. financial institutions.

3.What should I do if I made a mistake on my federal return that I have already filed?
It depends on the type of mistake that you made:

Many mathematical errors are caught in the processing of the tax return itself.
If you did not attach a required schedule the service will contact you and ask for the missing information.
If you did not report all your income or did not claim a credit, you are entitled to file an amended or corrected return using Form 1040X, Amended U.S. Individual Income Tax Return.

4. Is there an age limit on claiming my children as dependents?
Age is a factor in the qualifying child test, but a qualifying relative can be any age.

As long as the following dependency exemption tests are met, you may claim him or her:
Qualifying child or qualifying relative test
Dependent taxpayer test
Citizenship or resident test
Joint return test

5. If I claim my daughter as a dependent because she is a full-time college student, can she claim herself as a dependent when she files her return?
If you claim your daughter as a dependent on your income tax return, she cannot claim herself on her income tax return.

If an individual is filing his or her own tax return, and the individual can be claimed as a dependent on someone else’s return, the individual cannot claim his or her own personal exemption.
In this case, your daughter should check the box on her return indicating that someone else can claim her as a dependent.

6. How much does a student have to make before he or she has to file an income tax return?
If you are an unmarried dependent, you must file a tax return if your earned and/or unearned income exceeds certain limits.

To find these limits refer to Filing Requirements for Dependents in Publication 501, Exemptions, Standard Deduction and Filing Information.
Even if you do not have to file, you should file a federal income tax return to get money back if any of the following apply:
You had income tax withheld from your pay.
You qualify for the earned income credit.
You qualify for the additional child tax credit.

7. For head of household filing status, do you have to claim a child as a dependent to qualify?
In certain circumstances, you do not need to claim the child as a dependent to qualify for head of household filing status, such as when the qualifying child is unmarried and is your child, grandchild, stepchild, or adopted child.

8. What are the tax changes for this year?
For highlights of any tax changes for the current tax year please refer to the “What’s New” section for:

Form 1040 Instructions
Form 1040A Instructions
Form 1040EZ Instructions

9. How do I know if I have to file quarterly individual estimated tax payments?
If you owed additional tax for the prior tax year, you may have to make estimated tax payments for the current tax year.

You must make estimated tax payments for the current tax year if both of the following apply:

You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits.
You expect your withholding and credits to be less than the smaller of:
90% of the tax to be shown on your current year’s tax return, or
100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months.)

10. How do I request a copy of my tax return for last year?
If you need an exact copy of a previously filed and processed return and all attachments, you must complete Form 4506 (PDF), Request for Copy of Tax Return, and mail it to the IRS.

Use the address provided in the instructions to the form.
Submit a check or money order for $57, per tax year, made payable to the “United States Treasury.”
Copies are generally available for returns filed in the current and past 6 years.

In cases where an exact copy of the return is not needed, tax return and transcripts may be ordered.

The tax return transcript shows most line items contained on the return as it was originally filed, including any accompanying forms and schedules.
In most cases, a tax return transcript will meet the requirements for lending institutions for mortgage verification purposes.
The transcript can be ordered by completing a Form 4506-T (PDF) or calling 800-829-1040 and following the prompts in the recorded message.
There is no charge for the transcript and you should receive it in 10 business days from the time we receive your request.
Tax return transcripts are generally available for the current and past three years.

source: irs.gov