The U.S. Internal Revenue Service is mass-mailing Letter 6174 notices to taxpayers with virtual-asset transaction histories, prompting them to review whether past cryptocurrency activity was properly reported. Clinton Donnelly, CEO of CryptoTaxAudit, which provides crypto tax returns, gain calculations and forensic analysis, said the campaign has alarmed taxpayers, including the firm’s clients, who contacted the company. Donnelly estimates the IRS is sending about 10,000 notices a month. The campaign has operated since 2019 and was initially described as educational, but the mailings have increased pressure on recipients to revisit earlier filings. Letter 6174 and Letter 6174-A generally do not require a direct response, and receiving either notice does not establish a tax violation. Donnelly advised recipients to review their circumstances carefully before amending returns or submitting documents. Joel Schwartz, Ripple’s honorary chief technology officer and a board member, said he also received the mailing and discarded it as a compliance reminder.