The IRS already has many tools at its disposal to force taxpayers to pay delinquent tax debts. Recently, the IRS added another weapon to its arsenal. Now, taxpayers with significant tax deficiencies could be barred from traveling internationally, as the IRS is revoking or denying passport applications and renewals for taxpayers with significant tax liabilities. This raises potential complication for domestic travel as well. For taxpayers living in states whose driver's licenses and identification cards do not meet certain standards (as part of the REAL ID Act) their passports will no longer be available as a valid ID alternative for use with TSA while traveling by air within the United States.