As of 2015, the IRS maintains a list of hotlines and toll-free numbers for taxpayers on its website. Use this list to find the appropriate number based on the issue you need to resolve, the IRS explains.
In addition to phone numbers, the IRS also gives taxpayers numerous online resources. Use the Web page How to Contact the IRS to find solutions to various tax-related questions and locate contact information for various departments. Alternatively, use the online office locator tool to find your local IRS Taxpayer Assistance Center. Simply enter your ZIP code to find your local office, explains the IRS.