Tax Data, Immigration Enforcement, and the Privacy of Voluntary Compliance: The IRS–ICE Data-Sharing Controversy and Its Comparative Implications Across Five Common Law Jurisdictions-2026

Abstract

In early 2026, the United States government entered into a data-sharing arrangement between the Internal Revenue Service (IRS) and Immigration and Customs Enforcement (ICE) that would permit immigration authorities to access federal tax return information for the purpose of locating undocumented immigrants. In March 2026, the United States Court of Appeals for the District of Columbia Circuit was urged to maintain a district court injunction blocking the arrangement in Center for Taxpayer Rights et al., v. IRS et al., No. 26-5006. This article provides the first comprehensive legal and comparative analysis of the IRS–ICE arrangement. It examines the statutory framework governing taxpayer confidentiality under §6103 of the Internal Revenue Code, evaluates the agreement’s compatibility with the United States’ voluntary tax compliance architecture, and analyzes its constitutional implications under the First, Fourth, and Fifth Amendments. The paper further situates the controversy within a comparative framework by examining how Canada, Australia, New Zealand, and the United Kingdom have approached and uniformly rejected the use of tax authority data for immigration enforcement purposes. The article argues that the use of tax return data for immigration enforcement undermines the legal and institutional foundations of voluntary compliance, imposes substantial and under-acknowledged fiscal costs, and raises rule-of-law concerns that extend far beyond immigration policy. By eroding the confidentiality compact between the state and taxpayers, the IRS–ICE arrangement threatens the integrity of the tax system itself.