On Oct. 7, 2026, the IRS highlighted its partnership with His Majesty’s Revenue and Customs (HMRC), the United Kingdom’s tax authority, in developing HMRC’s Strengthened Reward Scheme. The IRS said its Whistleblower Office expertise helped HMRC establish the program quickly. HMRC launched the scheme in November 2025 to encourage reports of serious tax avoidance and evasion involving the wealthiest individuals and largest businesses. The IRS and HMRC said cooperation is intended to strengthen cross-border tax compliance and help identify global tax evasion. IRS Chief Executive Officer Frank J. Bisignano said the partnership could help deter large-scale, cross-border evasion and support enforcement in both countries. HMRC Chief Executive JP Marks recognized the role of informants in protecting tax systems and thanked the IRS for supporting the scheme’s development. The announcement describes how tax evasion can involve sophisticated arrangements, including offshore accounts, shell companies and fraudulent transfers spread across jurisdictions. The IRS said whistleblowers may provide tax authorities with specific, credible information that helps identify wrongdoing and ensure taxpayers meet their obligations. It cited accountants, bankers and executives as examples of people who may have relevant information. The IRS and HMRC encouraged people with specific, timely, significant and credible information about suspected tax-law violations to submit reports. In the United States, the IRS directs tipsters to its Whistleblower Office or IRS.gov/SubmitATip. In the United Kingdom, it points to the GOV.UK page for reporting serious tax avoidance or evasion. Examples listed in the announcement include undeclared foreign bank accounts and failure to file a Report of Foreign Bank and Financial Accounts (FBAR); hidden assets held through foreign trusts, foundations, financial instruments or anonymous entities in tax havens; money laundering; and transfer-pricing manipulation or illicit cross-border profit shifting by high-net-worth individuals. The source presents this as an enforcement and reporting initiative; it does not announce a change to individual tax rates or filing requirements.