IRS Tax Tip 2019-124, September 10, 2019 Tax professionals should learn the tell-tale signs that their office may have experienced a data theft. Such thefts could have resulted in fraudulent tax returns filed in their clients' names. Here is a list of warning signs that a tax professional or their office may have experienced a data theft: Their clients' e-filed returns are rejected by the IRS or state tax agencies. This happens because someone else already filed a tax return with their client's Social Security number. Clients who haven't filed tax returns begin to receive taxpayer authentication letters from the IRS. The IRS sends letters such as the 5071C, 4883C and 5747C to confirm a taxpayer's identity for a submitted tax return. Clients who haven't filed tax returns receive refunds. Clients receive tax transcripts that they didn't request. Clients who created an IRS Online Services account receive an IRS notice that their account was accessed. Clients who have an account get an IRS emails saying their account is disabled. Clients unexpectedly receive an IRS notice that an IRS online account was created in their names. The number of returns filed with the tax professional's Electronic Filing Identification Number is higher than the number of clients they have. Tax professionals or clients responding to emails that the firm did not send. Network computers running slower than normal. Computer cursors moving or changing numbers when the user is not even touching the keyboard. Network computers locking out employees. More information: Federal Trade Commission Safeguards Rule Publication 4557, Safeguarding Taxpayer Data PDF Small Business Information Security: The Fundamentals PDF by the National Institute of Standards and Technology Publication 5293, Data Security Resource Guide for Tax Professionals PDF e-News for Tax Professionals Subscribe to IRS Tax Tips