Any corporation that overpaid its estimated tax for the tax year may apply for a quick refund if the overpayment is: At least 10% of the expected tax liability. At least $500. Current Revision Form 4466 PDF Recent Developments Taxpayer Relief for Certain Tax-Related Deadlines Due To Coronavirus Pandemic -- 14-APR-2020 Other Items You May Find Useful All Revisions for Form 4466 About Publication 542, Corporations Other Current Products Related About Form 990-T, Exempt Organization Business Income Tax Return (and proxy tax under section 6033(e)) About Form 1120, U.S. Corporation Income Tax Return About Form 1120-C, U.S. Income Tax Return for Cooperative Associations About Form 1120-F, U.S. Income Tax Return of a Foreign Corporation About Form 1120-FSC, U.S. Income Tax Return of a Foreign Sales Corporation About Form 1120-H, U.S. Income Tax Return for Homeowners Associations About Form 1120-L, U.S. Life Insurance Company Income Tax Return