What is the IRS tax penalty for underpayment itself (approximately)? I'm not asking about late payments, just low withholdings.

I agree with Attorney Larson. Also, be aware that there are safe harbor rules whereby you can under withhold if you meet the safe harbor...

Send in you own return. Since someone already claimed you, you will not be able to efile and will need to file a paper return. The IRS will take...

Is a loan to my US citizen partner for the purchase of a house regarded as a gift and taxable.

This is something that you should consult with an attorney. As you state, there are several ways to structure this transaction and you should...

I'm 25, and my parents won't stop claiming me as dependent

Yes, you can claim your self and your parents will not be able to claim you. If they do the IRS will contact them and you and investigate who...

Tax question

Review the letter you were sent and see if there is a contact name. Call the contact and inform them what happened and offer to send the...

No you cannot file as single since you are married, but you can file as Married Filing Separately.

What can I do if my tax preparer file incorrect information concerning my 2007 mortgage?

Your facts do not present your situation clearly. This is something that you should see a tax professional on and get specific advise for your...

My mother claimed me on my taxes

File your own return claiming yourself and let your mother know you are claiming yourself and she needs to stop claiming you on her tax return.

How can I pass the CA Prop 13 tax rate on my house down to my daughter?

There is an unlimited exemption for a principal residence on a transfer between a parent and a child in Ca. For other properties it is limited to...

IC-DISCs for tax planning..

More facts would be required to respond to your question.