Residency Migration Reference
Moving from Guam to Illinois: Residency, Taxes, and What to Prove
The top income tax rate drops from 37% under the mirrored federal brackets; as low as roughly 25% of that (a 75% reduction) for up to 20 years for approved GEDA Qualifying Certificate holders in Guam to 4.95% (flat) in Illinois. Establishing Illinois residency correctly is what protects that benefit.
Residency Tests Side by Side
Guam's statutory residency test uses a 183-day threshold. Illinois does not use a simple day-count threshold; it applies a facts-and-circumstances test instead.
| Factor | Guam | Illinois |
|---|---|---|
| Statutory Residency Test | Guam, like the other four territories, has no day-count statutory residency overlay of its own. Bona fide residency is governed by the federal IRC section 937 three-part test: the presence test, the tax home test, and the closer connection test, all of which must be satisfied for the same tax year. DRT applies the identical federal standard used by the IRS. | Illinois has no statutory residency test of the New York or Minnesota type: no bright-line day count and no permanent place of abode prong. 35 ILCS 5/1501(a)(20)(A) defines a resident as an individual '(i) who is in this State for other than a temporary or transitory purpose during the taxable year; or (ii) who is domiciled in this State but is absent from the State for a temporary or transitory purpose during the taxable year.' Those are the only two routes to Illinois residency for an individual. Cain v. Hamer, 2012 IL App (1st) 112833, shows how far that departure from a day count runs: snowbird retirees who spent 1,666 days in Illinois against 1,700 in Florida across 1996 through 2004, an average well above 183 Illinois days a year, were held not to be Illinois residents. Day counts matter in Illinois as evidence of purpose and as inputs to the administrative presumptions, not as a threshold that decides residency by itself. |
| Domicile Test | Closer connection functions as Guam's domicile test under Treasury Regulation 1.937-1(c): the location of a permanent home, family, personal belongings, social/political/cultural/religious affiliations, routine banking, business activity, and the jurisdiction of a driver's license and voter registration are weighed against the total of U.S. and foreign-country contacts. Publication 570's own illustrative example uses a Guam/CNMI fact pattern (a hotel employee who splits time between the two) to show how the tax home and closer connection tests interact when someone has ties to more than one territory. | Illinois follows the traditional common-law domicile standard under 86 Ill. Adm. Code 100.3020: domicile is the place a person intends as their true, fixed, permanent home, and to which they intend to return whenever absent. A person can have only one domicile at a time, and it continues until a new one is established through both physical presence in the new location and demonstrated intent to abandon Illinois as the permanent home. The Department of Revenue looks at where a person votes, holds a driver's license and registers vehicles, banks, keeps professional relationships (doctor, lawyer, accountant), works, houses family, and belongs to clubs or religious institutions; no single factor controls. |
| Day Count Threshold | 183 days | No fixed threshold |
| Any Part of a Day Rule | Any part of a day physically present in Guam counts as a full presence day, and a day spent in both Guam and the mainland U.S. counts toward Guam. The standard exceptions for qualified medical treatment, presidentially declared disasters, mandatory evacuations, and a limited 30-day travel allowance apply under the Form 8898 instructions. | Not applicable in the statutory sense, because Illinois has no day-count threshold for an individual to cross. There is no any-part-of-a-day rule to apply. Days still get counted in Illinois practice, both because 86 Ill. Adm. Code 100.3020(f) presumes residency above nine months in the aggregate and presumes continued residency where an individual is present in Illinois more days than in any other state, and because the Department of Revenue's audit division reconstructs presence from credit card, toll, and travel records to test whether time in Illinois was temporary or transitory. |
| Presumptions | None published | 86 Ill. Adm. Code 100.3020(f) supplies four rebuttable presumptions in place of a statutory day test. An individual who spends in the aggregate more than nine months of any taxable year in Illinois is presumed to be a resident. An individual absent from Illinois for one year or more is presumed to be a nonresident. An individual receiving a homestead exemption on Illinois property under 35 ILCS 200/15-175 is presumed to be an Illinois resident. And an Illinois resident in one year is presumed to be a resident the following year 'if he or she is present in Illinois more days than he or she is present in any other state.' The presumptions 'are not conclusive and may be overcome by clear and convincing evidence to the contrary,' with the rule listing acceptable rebuttal evidence including location of spouse and dependents, voter and vehicle registration, driver's license, filing a resident return elsewhere, home ownership or rental agreements, the permanent or temporary nature of work assignments, location of professional licenses, location of medical providers, accountants and attorneys, club memberships and participation, and telephone or other utility usage over a duration of time. |
| Safe Harbors | 183-day presence test; 549-day / 3-year test; 90-day U.S. cap; Low U.S.-earned-income test; No significant U.S. connection | None published |
Leaving Guam
No widely published Guam-specific bona fide residency court case surfaced in research comparable to Vento (USVI) or Karakashian (Puerto Rico). The exposure runs through the same federal IRC section 937 framework that applies across all five territories: an examiner reconstructing whether someone claiming Guam residency actually met the presence, tax home, and closer connection tests, particularly for GEDA Qualifying Certificate beneficiaries whose real business operations or family life stayed on the mainland.
Trailing Income
As with the other mirror-code territories, gains on investment property owned before becoming a bona fide Guam resident are subject to a 10-year sourcing rule under Treasury Regulation 1.937-2(f) that can keep pre-move appreciation taxable outside Guam even after relocating, unless the taxpayer makes the special holding-period allocation election in Publication 570.
Part-Year Filing
A bona fide Guam resident generally files one return, Form 1040GU, with DRT on worldwide income and has no separate federal filing obligation for that year if the Guam return is properly filed and full tax paid. Someone who is not a full-year bona fide resident but has Guam-source income files a U.S. return with the IRS and attaches Form 5074 (Allocation of Individual Income Tax to Guam or the CNMI) if adjusted gross income is $50,000 or more and Guam-source gross income is $5,000 or more, to divide the tax between the jurisdictions.
Enforcement Methods
Common Exit Mistakes
Establishing Illinois Residency
| Action | Agency | Deadline |
|---|---|---|
| Obtain an Illinois driver's license | Illinois Secretary of State | within 90 days of establishing residency (out-of-state license valid until then) |
| Register any vehicle kept in Illinois, with Illinois insurance in place first | Illinois Secretary of State, Vehicle Services | within 30 days of establishing residency |
| Register to vote | Illinois State Board of Elections | online and mail registration closes 16 days before an election; grace-period in-person registration and voting runs from 27 days before Election Day through Election Day |
Declaration of Domicile
Illinois has no formal declaration-of-domicile filing comparable to Florida's county-level process. Domicile is established through conduct alone: buying or leasing a home, getting the Illinois license and plates, registering to vote, and shifting the pattern of where professional, banking, and family life actually happens.
Homestead
The General Homestead Exemption reduces the equalized assessed value of an owner-occupied principal residence by up to $10,000 in Cook County, $8,000 in the counties bordering Cook, and $6,000 elsewhere, and requires ownership and occupancy as of January 1 of the tax year. It functions as useful domicile evidence for someone establishing Illinois residency, since applying for it requires attesting the home is a principal residence, and county assessors can cross-check driver's license and voter registration addresses against the exemption claim.
Voter Registration
Register online through the Illinois Online Voter Registration Application, by mail, or in person; online and mail registration closes 16 days before an election, with grace-period registration and same-day voting available from 27 days before Election Day through Election Day itself. https://ova.elections.il.gov
Vehicle Registration Deadline
30 days
New Resident Tax Traps
A new full-year Illinois resident is taxed on worldwide income from the date Illinois residency begins, computed on Form IL-1040 with Schedule NR handling the split year. Because Illinois has no capital gains preference, a large gain realized right after establishing residency (stock sale, business sale, Roth conversion) is taxed at the full 4.95% flat rate with no bracket cushion the way some other states offer at lower income levels.
What Changes on Tax
Guam Top Rate
37% under the mirrored federal brackets; as low as roughly 25% of that (a 75% reduction) for up to 20 years for approved GEDA Qualifying Certificate holders
Illinois Top Rate
4.95% (flat)
Moving from Guam to Illinois drops the top marginal income tax rate from about 75% to about 4.95%, a reduction of roughly 70.05 percentage points.
Withholding Reciprocity
Guam and Illinois do not have a wage-withholding reciprocity agreement with each other, so this move follows ordinary source-state and resident-state filing rules rather than a reciprocity exception.
Community Property Transition
Guam and Illinois both use common law, equitable-distribution marital property rules, so no community property transition applies to this move.
Beyond Income Tax
Guam
Capital gains: Capital gains follow the same rates as the mirrored federal code; there is no separate Guam capital gains schedule. A Qualifying Certificate from the Guam Economic Development Authority (GEDA) can reduce the effective tax rate, including on qualifying business-related gains, for an approved project.
Estate or inheritance tax: Guam has no separate territorial estate or inheritance tax; federal estate tax rules apply through the mirror code framework to Guam-domiciled decedents, administered locally by DRT rather than the IRS.
Property tax: Real property tax rates run roughly 0.5% to 1% of assessed value annually, among the lowest effective property tax burdens under the U.S. flag, and Qualifying Certificate holders can receive a full real property tax exemption for up to 10 years on an approved project.
Sales tax: Guam has no general retail sales tax. Instead it imposes a 5% Business Privilege Tax (BPT, Guam's gross receipts tax) on businesses and a matching 5% use tax on imported personal goods, both of which GEDA Qualifying Certificate holders can have substantially abated.
Illinois
Capital gains: No preferential rate. Capital gains are taxed as ordinary income at the same 4.95% flat rate as wages.
Estate or inheritance tax: Illinois has an estate tax with a $4 million exemption per estate that is not indexed for inflation and is not portable between spouses. Rates are graduated from roughly 0.8% up to 16% on the amount above the exemption. There is no separate inheritance tax.
Property tax: Illinois has the highest statewide effective property tax rate in the country, around 1.92% of home value, more than double the national median. The General Homestead Exemption reduces the taxable assessed value of an owner-occupied principal residence by up to $10,000 in Cook County, $8,000 in counties bordering Cook, and $6,000 elsewhere.
Sales tax: State base rate is 6.25%, but local home-rule and county taxes push combined rates as high as 11.5% in parts of Cook, Kane, and Warren counties; the effective statewide average is closer to 8.9%.
Who This Move Applies To
Travel Nurses
In Guam
Guam is not a major travel-nurse assignment market compared to the 50 states, but Guam Memorial Hospital and private facilities do draw contract clinical staff; the underlying federal tax-home analysis is identical to any state, requiring genuine maintenance of and return to a Guam home between assignments to sustain a Guam tax-home claim.
In Illinois
Illinois has no statutory day-count test to trip, so a travel nurse not domiciled in Illinois does not become an Illinois resident merely by crossing a day threshold on a long assignment. What creates exposure instead is the temporary or transitory question and the 100.3020(f) presumptions: an assignment structured as a series of renewals that keeps a nurse in Illinois more than nine months of a year, or more days than in any other state, supports a presumption of residency that must be rebutted by clear and convincing evidence, and the permanent or temporary nature of the work assignment is named in the rule as relevant evidence. The more common Illinois exposure is the reverse pattern, where a nurse claims a Florida or Texas tax home but actually lives in and pays Illinois-area rent for most of the year; Illinois-source wages for days actually worked in Illinois are taxable to any nonresident nurse regardless of claimed tax home.
Professional Athletes
In Guam
No major U.S. professional sports franchise is based in Guam, so there is no home-team jock-tax apportionment regime specific to the territory. Visiting athletes or performers earning income from events physically held in Guam owe Guam-source tax on income attributable to that work under the mirrored federal withholding framework administered by DRT.
In Illinois
Illinois taxes nonresident professional athletes on a duty-day basis: Illinois-source income equals total compensation multiplied by the ratio of duty days in Illinois (games, practices, mandatory team functions) to total duty days for the season; mere travel through Illinois without a game or team event does not create a duty day. This applies to visiting teams playing the Bears, Bulls, Blackhawks, White Sox, and Cubs, and Illinois is regarded by practitioners as an aggressive, well-enforced jock-tax state that historically extended the tax reciprocally to any state that taxed Illinois-based athletes.
Snowbirds, Long Visitors, and RVers
In Guam
A mainland resident who buys a Guam property and spends significant time there while keeping a permanent mainland home risks failing the closer connection test even with a solid day count, unless family, banking, and business ties also shift to Guam. Publication 570's own example addresses a related pattern directly: someone with ties to both Guam and the CNMI must determine which is the actual tax home based on where their regular place of business is located, not simply where they own property.
In Illinois
The Illinois snowbird risk runs entirely through the 100.3020(f) presumptions, not through a day threshold. A retiree who keeps the Illinois house and spends more than nine months there risks the nine-month presumption of residency, and a former Illinois resident is presumed to still be one in the following year if present in Illinois more days than in any other state, which is a comparison a snowbird splitting a year can lose well short of any traditional threshold. The favorable counterweight is Cain v. Hamer, 2012 IL App (1st) 112833, where retirees who split time nearly evenly (1,666 Illinois days against 1,700 Florida days across 1996 through 2004) were held nonresidents, with the court weighing nexus evidence such as Florida licenses, voter registration, a Florida declaration of domicile, club spending, and credit card data showing 73% of expenditures and 61% of transactions outside Illinois. Illinois's General Homestead Exemption is a specific cross-check point if a person claims Florida domicile but keeps the Illinois exemption active.
Remote Workers
In Guam
Guam has no convenience-of-the-employer rule of its own, but a mainland employer's own state convenience rule can still reach a Guam-based remote worker's wages if the employer continues to treat them as mainland-sourced. Guam's IRC section 931 exclusion for bona fide residents' Guam-source income is valuable, but only applies cleanly once the employer correctly treats the work as Guam-sourced and DRT-withheld rather than leaving it entangled with a mainland payroll system.
In Illinois
Illinois has no convenience-of-the-employer rule. A nonresident who works remotely from another state for an Illinois-based employer is generally not taxed by Illinois on those wages, because Illinois sources employee compensation to where the services are physically performed, not to the employer's location. This makes Illinois meaningfully less sticky for remote workers than New York or a handful of other convenience-rule states.
Military
In Guam
Guam hosts significant U.S. military presence (Andersen Air Force Base and Naval Base Guam) and follows the federal Servicemembers Civil Relief Act (SCRA) and Military Spouses Residency Relief Act (MSRRA): a servicemember's home-of-record does not change solely due to Guam orders, and a civilian spouse can elect to keep the servicemember's tax residence. A servicemember who qualified as a bona fide Guam resident before deployment elsewhere does not lose that status due to absence under military orders, but being stationed on Guam under orders alone does not create bona fide residency.
In Illinois
Illinois follows the federal Servicemembers Civil Relief Act and Military Spouses Residency Relief Act. A servicemember whose home of record is Illinois remains an Illinois domiciliary for tax purposes regardless of duty station unless they take affirmative steps to change domicile, while a servicemember stationed in Illinois on orders, and their qualifying spouse, does not become an Illinois resident solely because of the posting, and military pay is not Illinois-source income for a nonresident servicemember stationed there.
Airline Crew
In Guam
Guam's A.B. Won Pat International Airport is a hub connection point for trans-Pacific carriers, and the federal carve-out at 49 U.S.C. section 40116, limiting taxation of air carrier employees to their state or territory of residence and, in limited cases, a jurisdiction where they earn more than half their pay, applies to Guam the same way it applies to the 50 states. Crew who are bona fide Guam residents owe Guam tax on their wages under the mirrored federal framework rather than IRS tax on Guam-source pay.
In Illinois
Federal law (49 U.S.C. §40116) limits states to taxing airline employee compensation only in the employee's state of residence and any state where more than 50% of pay is earned. This protects flight crew based at O'Hare or Midway who are domiciled outside Illinois from having their full compensation pulled into Illinois taxation solely because their duty station is in Illinois.
Tools for This Move
Guam to Illinois FAQ
Does Guam have its own separate income tax system like Puerto Rico?+
No. Guam uses a mirror code under 48 U.S.C. section 1421i, meaning it applies the U.S. Internal Revenue Code word for word with 'Guam' substituted for 'United States.' You pay the same 10% to 37% federal brackets, just to Guam's Department of Revenue and Taxation instead of the IRS, which is a fundamentally different structure from Puerto Rico's or American Samoa's independently legislated tax codes.
Does Illinois have a 183-day rule like New York or Minnesota?+
No. This is the single most common misconception about Illinois residency. 35 ILCS 5/1501(a)(20) contains no day-count threshold and no permanent place of abode prong; a resident is someone in Illinois for other than a temporary or transitory purpose, or an Illinois domiciliary absent for a temporary or transitory purpose. What Illinois has instead are the rebuttable presumptions in 86 Ill. Adm. Code 100.3020(f), including a presumption of residency above nine months in the aggregate and a presumption that a prior-year resident remains one if present in Illinois more days than in any other state. The practical difference is real in both directions: crossing 183 Illinois days does not by itself make you a resident, and staying under 183 does not by itself make you a nonresident.
If I get a GEDA Qualifying Certificate, do I automatically qualify as a Guam resident for tax purposes?+
No. A Qualifying Certificate sets up eligibility for a tax reduction, generally up to a 75% income tax reduction for up to 20 years in the standard category, but you must still independently satisfy the federal presence, tax home, and closer connection tests every year, and GEDA and DRT can review whether the underlying business and residency are genuine throughout the certificate term.
If I move to Florida but keep my Chicago condo, will Illinois still tax me?+
Keeping the condo does not by itself make you taxable, because Illinois has no permanent place of abode test that a retained condo could trigger. The risk runs through purpose and presumptions instead. If you spend more than nine months of the year in Illinois, or simply more days there than in any other state after a year as an Illinois resident, the Department gets a presumption of residency you can rebut only by clear and convincing evidence. Continuing to claim the General Homestead Exemption on the condo is worse than the condo itself, since that alone creates its own presumption of Illinois residency and is a cross-check Illinois auditors run directly against a claimed out-of-state domicile.
How many days do I need to spend in Guam to be a bona fide resident?+
183 days in the tax year is the cleanest path, but there are four alternatives: 549 days across the current and two prior years with at least 60 days each year, 90 days or fewer in the U.S., $3,000 or less in U.S.-source earned income with more Guam days than U.S. days, or no significant U.S. connection at all. Meeting a presence prong alone is not enough; the tax home and closer connection tests must also be satisfied.
Does Illinois have a convenience-of-the-employer rule for remote workers?+
No. Illinois sources employee wages to where the work is physically performed, not to where the employer is headquartered. A nonresident who works remotely from another state for a Chicago-based employer generally is not taxed by Illinois on those wages, which is a meaningful difference from convenience-rule states like New York, and it means remote workers face less Illinois exposure after moving away than they might expect.
I split time between Guam and the CNMI. Which one is my tax home?+
Your tax home is your regular or main place of business or employment, regardless of where you also own property or spend leisure time. The IRS's own Publication 570 example addresses this exact situation: a hotel worker employed seasonally in Guam but living the rest of the year in the CNMI was found to have a Guam tax home because that's where the regular place of business was, even though the CNMI held stronger personal and social ties.
How do I file my Illinois taxes for the year I move out of state?+
File Form IL-1040 together with Schedule NR, the Nonresident and Part-Year Resident Computation of Illinois Tax. Schedule NR splits your income between the period you were an Illinois resident, which is taxed in full, and the period after you became a nonresident, when only Illinois-source income is taxed. Skipping Schedule NR and simply filing as a full-year nonresident in your move year is a common and easily flagged mistake.
What tax return do I file if I'm a bona fide Guam resident?+
You generally file Form 1040GU with Guam's Department of Revenue and Taxation reporting your worldwide income, and you're not separately liable to file with or pay the IRS for that year as long as the Guam return is properly filed and the tax fully paid. If you're not a full-year bona fide resident but have Guam-source income, you file with the IRS and may need to attach Form 5074 to allocate tax between the jurisdictions.
I work in Illinois but live in Wisconsin. Do I have to file two state returns?+
Illinois has reciprocity with Wisconsin, Iowa, Kentucky, and Michigan, so a Wisconsin resident working in Illinois generally does not owe Illinois tax on those wages and should not have Illinois tax withheld; instead, only Wisconsin taxes that income. If Illinois tax was withheld in error, you file for a refund from Illinois rather than claiming a credit, and you report the income on your Wisconsin return as usual.
Can I keep my mainland home after moving to Guam?+
You can own it, but keeping it available as a livable home for your own use works against you on the closer connection test, which compares your Guam ties to the total of your U.S. and foreign ties. Renting it out at fair market value with limited personal-use days is a safer pattern than leaving it available for regular stays.
Will keeping the homestead exemption on my Illinois house hurt me if I claim Florida residency?+
Yes, it's a direct contradiction auditors specifically look for. The General Homestead Exemption requires the property to be your owner-occupied principal residence as of January 1, so continuing to receive it while filing as an Illinois nonresident and claiming Florida domicile undercuts your own position. If you've genuinely moved, removing the exemption is one of the concrete steps that supports your new domicile claim.
Considering the reverse move?
Illinois to Guam
Moving the other direction is a different fact pattern, not a mirror image: exit risk and establishment mechanics both flip.
View the Illinois to Guam guideGuam to Illinois Reading
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ResidencyIQ organizes public residency research into a reviewable reference. It does not provide legal or tax advice. Consult a qualified professional before making a residency decision.
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