Blog · 14 October 2026

Tax Residency vs Immigration Status: Form 1040 Citizenship Checkbox, Substantial Presence and What US CPA Firms Should Tell Clients

By Keshav Bansal, CA

Tax residency is not the same as immigration status—and that distinction is back in the headlines. On October 1, 2026, eleven Senate Finance Democrats led by Sens. Ben Ray Luján (D-N.M.) and Ron Wyden (D-Ore.) wrote IRS Chief Executive Officer Frank Bisignano urging him to drop a proposed citizenship and work-authorization checkbox from the final 2026 Form 1040. Accounting Today and the senators’ press materials report the request; a response was asked for by October 22, 2026. For US CPA firms, the practical lesson is older than the letter: who files Form 1040 versus Form 1040-NR turns on tax residency tests, not on immigration checkboxes.

What the senators asked the IRS to do

Per Senator Luján’s October 2, 2026 press release and the letter text posted with it, Luján and Wyden led nine colleagues—Sens. Cortez Masto, Padilla, Welch, Heinrich, Van Hollen, Rosen, Murray, Booker and Warren—in asking Bisignano to remove the newly proposed citizenship and work authorization checkbox from the final 2026 Form 1040. The letter argues the question serves no clear tax-administration purpose, notes that nonresidents already file Form 1040-NR, and cites IRS checks of work authorization against Social Security Administration data. It also presses for a delayed update to IRS tax gap estimates and asks whether any statute requires the checkbox.

The letter cites a Yale Budget Lab estimate that “weaponizing tax filing” could cost $313 billion over the next decade and endanger the $66 billion unauthorized workers currently pay each year. Attribute carefully: the Budget Lab’s April 8, 2025 analysis estimates about $313 billion ($147–479 billion) in lower federal income and payroll tax revenue over 2026–35 from reduced compliance after IRS–ICE data sharing—not a separate score of the checkbox alone. Exact checkbox wording is not in the Senate letter PDF; until an official IRS draft or final form is confirmed, treat the item as proposed.

Tax residency is not immigration status

Per IRS Topic no. 851, an alien for federal income tax purposes is an individual who is not a U.S. citizen. Aliens are resident aliens or nonresident aliens, and the two are taxed differently. You are a resident alien for a calendar year if you are not a U.S. citizen and you meet either the green card test or the substantial presence test for that year.

Under the green card test (Topic no. 851 and the IRS green card residency page), you are a resident alien if at any time during the calendar year you are a lawful permanent resident—generally if USCIS has issued Form I-551 (Permanent Resident Card). That status continues until it is taken away or is administratively or judicially determined to have been abandoned.

Under the substantial presence test (Topic no. 851 and the IRS substantial presence page), you are treated as a resident alien if you are physically present in the United States on at least:

• 31 days during the current year, and
• 183 days during the three-year period that includes the current year and the two years immediately before it, counting all days in the current year, one-third of the days in the first preceding year, and one-sixth of the days in the second preceding year.

Presence-day exceptions apply (certain Canada/Mexico commuters, brief transit, crew members, certain medical stays, and many F/J/M/Q “exempt individuals”). Closer-connection and treaty tie-breaker rules can still produce nonresident treatment. Dual-status arrival or departure years follow Publication 519—not immigration slogans.

Form 1040 vs Form 1040-NR—and when Form W-7 matters

Per Topic no. 851, resident aliens follow the same tax laws that apply to U.S. citizens: they report worldwide income and generally file Form 1040 or Form 1040-SR. Nonresident aliens who must file generally use Form 1040-NR for U.S.-source and effectively connected income (effectively connected income on page one; non-effectively connected FDAP on Schedule NEC, typically at 30% or a lower treaty rate).

People who must file but do not have—and are not eligible for—a Social Security number apply for an ITIN on Form W-7. Per the IRS “About Form W-7” page, an ITIN is a nine-digit number for federal tax purposes only; it is not work authorization. Related refundable-credit / alien-status intake also appears in the draft Schedule 3-A debate—see our draft Schedule 3-A guide.

What “tax gap” means in this fight

Per the IRS tax gap statistics page, the gross tax gap is true tax liability for a given year that is not paid voluntarily and on time (nonfiling, underreporting and underpayment). The IRS projects $696 billion for tax year 2022. The senators’ letter says the October 2024 report projected nearly $700 billion for TY2022 and that a TY2023 update once expected in fall 2025 is almost a year late. For audit-rate context, see our IRS audit rate and CP2000 guide; for withholding, see the draft 2027 Form W-4 overview.

What US CPA firms should tell clients

• Separate tax residency from immigration advice. Green card and substantial presence are tax tests; visa and work-authorization questions belong with immigration counsel.
• Pick the right return before debating a checkbox. Residents generally use Form 1040 on worldwide income; nonresidents who must file generally use Form 1040-NR.
• Document day counts early. Travel calendars and Form 8843/8840 packages matter more than form rumors.
• Use ITINs only when IRS rules call for them. Form W-7 is for people who need a TIN to file and cannot get an SSN—not employment authorization.
• Watch the final 2026 Form 1040. Until Bisignano responds and the final form ships, describe the citizenship/work-authorization item as proposed.

A short firm checklist

• Add a tax-residency intake block: citizenship, green card, days in the U.S. this year and the prior two years, treaty/closer-connection claims, and dual-status dates.
• Compute substantial presence on a worksheet (31-day current-year gate + 183-day weighted total) before choosing Form 1040 vs 1040-NR.
• Flag ITIN applicants for Form W-7 documentation timing; do not treat an ITIN as work authorization.
• Diary the senators’ October 22, 2026 response request and official Form 1040 releases before changing organizers.
• When clients ask about “tax gap” talking points, quote the IRS gross tax gap definition and attribute Yale Budget Lab figures to the Budget Lab (and the letter’s citation), not to Tax Brew scoring.

Where this fits for Tax Brew readers

Residency worksheets, day-count workpapers and Form 1040-NR / W-7 packages need careful prep while signing professionals and counsel own status and immigration calls. If your firm needs extra capacity on that preparation work, outsourced tax prep and bookkeeping support for US CPA firms can help. Email info@taxbrewglobal.com.

Check current guidance: this article summarizes the October 1, 2026 Luján–Wyden letter (Senator Luján press release, October 2, 2026; Accounting Today coverage), Yale Budget Lab “The Potential Impact of IRS-ICE Data Sharing on Tax Compliance” (April 8, 2025), IRS Topic no. 851, the IRS substantial presence and green card residency pages, IRS “Taxation of nonresident aliens,” IRS “About Form W-7,” and the IRS tax gap statistics page (TY2022 projected gross tax gap $696 billion). Confirm the final 2026 Form 1040, Pub. 519 and current Code before advising. This is general information, not tax, immigration or legal advice. Sources as of 14 October 2026.