Hi and welcome to Just Answer!
If your did not timely filed your 2008 tax return - the statute of limitation to claim a refund or a credit started on Apr 15, 2009 and run out on Apr 15, 2012.
You still may amend your 2008 tax return - and if you have any unpaid tax liability - that liability will be reduced - but generally - no refund may be claimed.
If you had NOL in 2008 - it should be carried backward for two years - and if anything left - that amount will be carried over to 2009 and following years.
Specifically for NOL - there is seven years stature of limitation - so you might be able to claim refund if it is based on NOL.
Se for reference - http://www.law.cornell.edu/uscode/usc_sec_26_00006511----000-.htmlClaim for credit or refund of an overpayment of any tax imposed by this title in respect of which tax the taxpayer is required to file a return shall be filed by the taxpayer within 3 years from the time the return was filed or 2 years from the time the tax was paid, whichever of such periods expires the later, or if no return was filed by the taxpayer, within 2 years from the time the tax was paid. Claim for credit or refund of an overpayment of any tax imposed by this title which is required to be paid by means of a stamp shall be filed by the taxpayer within 3 years from the time the tax was paid.
Let me know if you need any help.
1. There is no statute of limitation on audit.
2. The statute of limitation to claim a refund or credit is not started 03/10 just because you filed late - but on Apr 15, 2009 when your tax return was due. However if you paid taxes on 03/10 - the statute of limitation will run two years after that date.
3. The statute of limitation on assessment is not started at all if your tax return was not filed. But it will be three years after you actually filed your tax return. In your situation - the IRS may assess additional tax liability up to 03/13.