What share of Social Security payroll taxes comes from workers using false or borrowed SSNs versus ITIN filers?
Executive summary
Available public reporting shows that workers using ITINs have paid billions in payroll-related taxes, but the sources provided do not offer a reliable, up-to-date percentage of total Social Security payroll taxes attributable to ITIN filers — and they offer no quantified estimate for workers using false or borrowed Social Security numbers (SSNs) [1] immigrationcouncil.org/research/facts-about-individual-taxpayer-identification-number-itin" target="_blank" rel="noopener noreferrer">[2]. Consequently, any precise “share” split between false/borrowed-SSN wages and ITIN-reported wages cannot be calculated from the materials supplied; what follows is a careful synthesis of what the record does say and where the evidence is missing.
1. What the sources say about ITIN payers and payroll taxes
Multiple authoritative summaries and advocacy reports make clear that ITINs exist to enable people without SSNs to file tax returns and pay federal taxes, and that ITIN holders have in aggregate paid billions in payroll and other federal taxes — for example, the IRS and related reporting produced figures such as an estimated $5.5 billion in payroll and Medicare taxes in 2015 and an IRS-cited “over $9 billion” in annual payroll taxes reported in 2014, though the latter lacks a clean methodological breakdown in the public snippet provided [1]. The American Immigration Council emphasizes that ITINs were created so people without SSNs — including undocumented immigrants — can pay taxes, and documents recent policy shifts affecting data sharing between Treasury/IRS and immigration authorities [2]. The IRS also confirms ITINs are for federal tax purposes only and do not entitle holders to Social Security benefits or EITC eligibility [3].
2. Why these ITIN dollar figures don’t translate to a precise “share” of Social Security payroll taxes
To convert a headline dollar figure for ITIN-reported payroll taxes into a percentage of total Social Security payroll taxes requires contemporaneous totals for the relevant tax base and clear delineation of which taxes are counted (Social Security only, Social Security plus Medicare, employer vs. employee shares, and self-employment equivalents). The documents provided do not supply those matching denominators or consistent annual comparisons, so they cannot produce a rigorous percentage of total Social Security payroll taxes coming from ITIN filers [1] [3]. Independent payroll thresholds and the wage base (which determine taxable earnings subject to Social Security withholding) also changed over time, complicating apples-to-apples comparisons without fresh data [4] [5].
3. What the sources say — and do not say — about false or borrowed SSNs
The Social Security Administration and congressional materials acknowledge misuse and identity-theft risks involving SSNs and ITINs, and the SSA has policies around verifying SSNs and employer records, but the supplied excerpts do not provide quantified estimates of wages paid under false or borrowed SSNs or how much payroll tax revenue they produced [6] [7]. The IRS and SSA have taken steps to strengthen documentation and employer reporting, but the materials offered do not report a measurable share of FICA (Social Security) tax attributable to workers using fraudulently obtained or borrowed SSNs [6].
4. Implications, competing narratives, and data gaps
Advocates and researchers cite ITIN tax payments to underscore that non-SSN filers contribute to federal revenues and social insurance financing [2] [1], while others—often in policy debates about immigration and benefits—highlight SSN misuse as a governance and enforcement problem [6]. The supplied evidence supports both broad statements but leaves the central quantitative question unanswered: there is no reliable, sourced percentage split between Social Security payroll taxes from ITIN filers versus those attributable to false/borrowed SSNs in the documents provided [6] [1]. Filling that gap would require IRS or SSA data that separately tabulates Social Security taxable wages reported under ITINs and a vetted estimate of wages reported under SSNs later determined to be false or borrowed, matched to the same year’s total Social Security payroll tax base — data not present in the current record.
5. Bottom line
The record shows ITIN filers have contributed billions to payroll and related federal taxes, but with the materials provided, it is impossible to state what share of Social Security payroll taxes comes from ITIN filers versus workers using false or borrowed SSNs; the sources lack the consistent, disaggregated totals and direct estimates needed to compute those shares [1] [6]. Any definitive percentage claim would require new, disaggregated IRS/SSA analysis or an authoritative academic study that the current sources do not supply.