The IRS sent tax lien notices to the wrong addresses for taxpayers even though the agency had the correct addresses in its system, according to a July report by the U.S. Treasury Inspector General for Tax Administration (TIGTA). Though the agency re-sent the notices, the incorrect mailings were potentially illegal because the IRS is required by statute to notify taxpayers at their last known address within five days of filing Form 668(Y)(c), Notice of Federal Tax Lien. IRS…