Why do people receive letters directing them to ID verification on the IRS website?

People receive letters directing them to ID verification on the IRS website when the agency suspects identity theft on tax returns, according to the IRS. The returns have names and Social Security numbers of actual taxpayers. In order to verify their identities, individuals must accurately answer a number of questions.

After taxpayers verify their identities, they inform the IRS whether they submitted the suspicious returns, the agency explains. If so, the IRS finishes processing the return and issues any refund in about six weeks. The IRS asks taxpayers to verify their identities only through Letter 5071C. The agency does not request this action through email or over the phone.