Washington ? Need help with your taxes? Good luck reaching the IRS. Three out of 10 people who call the toll-free help line this tax season won’t get through to a human being — and that’s if the agency meets its goals for service.

Callers lucky enough to get through will have to wait on hold an average of 12 minutes, a level of service deemed unacceptable in a report issued Wednesday by National Taxpayer Advocate Nina E. Olson.

Such poor service “will cause problems for taxpayers and the IRS alike, as some taxpayers give up and don’t bother to file or they make avoidable errors that the IRS then must devote resources toward resolving,” said Olson, an independent watchdog within the IRS.

The IRS said it has been inundated with an unprecedented number of calls the past two years from taxpayers with questions about temporary tax breaks passed by Congress to help revive the economy — a phenomenon that is expected to continue this year.

To help, the agency has upgraded its Web site, posting answers to frequent questions, including the status of tax refunds.

In 2009, the agency received 94 million calls.

The toll-free help line is 800-829-1040.