There is a statute of limitation on claiming a refund - which is three years in most situations.

The statute of limitation starts when the tax return is due.

Thus - the statute of limitation on 2006 tax return started on Apr 15, 2007 and will run out of Apr 15, 2010. If you file your tax return before that date and claim a refund - you should receive it.

You also may claim a refund for 2007, 2008, and 2009.

You still may file your tax returns for 2005 and prior years - but would not receive any refunds due to the statute of limitation run out.

As long as you would file and sign a joint tax return - your both will be help responsible for all information and tax liability resulted from that tax return.

Both taxpayers are jointly and severally liable for the tax and any additions to tax, interest, or penalties that arise as a result of the joint return even if they later divorce. Joint and several liability means that each taxpayer is legally responsible for the entire liability.

In some cases, a spouse can get relief from joint and several liability. There are three types of relief from joint and several liability for spouses who filed joint returns:

1. Innocent Spouse Relief for additional tax you owe because your spouse or former spouse failed to report income, reported income improperly or claimed improper deductions or credits.
2. Relief by Separation of Liability provides for the allocation of additional tax owed between you and your spouse or former spouse because an item was not reported properly on a joint return. The tax allocated to you is the amount you are responsible for.
3. Equitable Relief may apply when you do not qualify for innocent spouse relief or separation of liability relief for something not reported properly on a joint return. You may also qualify for equitable relief if the correct amount of tax was reported on your joint return but the tax remains unpaid.

Form 8857, Request for Innocent Spouse Relief, or a written statement containing the same information required on Form 8857, which is signed under penalties of perjury, must be filed in order to request innocent spouse relief, separation of liability, or equitable relief. You may also refer to Publication 971, Innocent Spouse Relief, for more information. If you request relief from joint liability, the IRS is required to notify the spouse with whom you filed the joint return of your request and allow him or her to provide information for consideration regarding your claim.