You have to use the 1040 when you claim the credit on the 5405. But if you already filed your 2008 return and you want to claim the credit on your ’08 return, then you will need to file Form 1040X to claim the credit. You will have to mail in with the 1040X the 5405, a copy of the HUD-1 statement and the seals. This will take 16 to 20 weeks to process.

HR Block Tax Advisor i

If you haven’t filed at all, use form 1040. This is the only form with a line for it.
If you have already filed, use form 1040x, starting at line 10. The credit goes on line 15.

You’re confused. You use a 1040X with form 5405, and include copy of HUD-1 from closing. Get copy of return you filed for 2008 taxes, and file an amended return. Takes 12-18 weeks for processing. Otherwise you wait until you file 2009 taxes.