Hmmm...
Alan thinks QB2004 tax tables end in May 2007, but payroll will continue to function until Feb 2008. I assume that means calculate taxes with last tax table.
Amy thinks QB2004 payroll stops functioning altogether in May 2007.
From the link Amy posted: "QuickBooks 2004 - QuickBooks Payroll (formerly Do-It-Yourself Payroll service) On May 31, 2007, we are discontinuing QuickBooks 2004 Payroll and QuickBooks Payroll with Direct Deposit for QuickBooks 2004. If you are a user of QuickBooks 2004 you will need to upgrade to a more recent version of Quick Books prior to May 31, 2007. After you upgrade, your payroll subscription will renew automatically at your next bill date. If you do not upgrade, a prorated refund will be issued for the unused portion of your payroll subscription."
That's a little murky. At first glance, one would think payroll ceases to function May 2007. However, I think Alan is probably right that just tax table updates stop, and calculation will continue until Feb 15, 2008. However, tax forms for 2007 year end will likely be out of date, so an upgrade will be required before then if the user wants to produce the forms from within QB.