Home buyers wanting to utilize the newly improved home buyer tax credit have to wait until they complete the purchase and close or, in the case of new construction, take up residence to claim the credit, the Internal Revenue Service (IRS) says in a newly released filing guidance. For households that won't close before the April 15 tax-filing deadline, the guidance provides four options: 1) file an extension, 2) file now, amend later, 3) amend the 2008 tax return, or 4) claim the credit in 2009 rather than 2008. Read the IRS guidance .