Times to call the IRS vary from 7 a.m. to 7 p.m., Monday through Friday, for the individual telephone assistance phone number, to 8 a.m. to 5 p.m. Monday through Friday for the exempt organization phone number, the IRS notes. Most phone lines are open 7 a.m. to 7 p.m.
A detailed outline of times to call the IRS can be found on IRS.gov. Taxpayers can call the IRS for questions regarding tax issues, set up a payment plan, order a tax transcript or check the status of a refund, explains the IRS. There are phone numbers available for taxpayers who live outside of the United States.