Residency Migration Reference
Moving from Guam to South Carolina: 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 6% in South Carolina. Establishing South Carolina residency correctly is what protects that benefit.
Residency Tests Side by Side
Guam's statutory residency test uses a 183-day threshold. South Carolina does not use a simple day-count threshold; it applies a facts-and-circumstances test instead.
| Factor | Guam | South Carolina |
|---|---|---|
| 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. | South Carolina has no day-count statutory residency test. The Department of Revenue's own guidance states plainly: 'Unlike some states that tax a person as a resident who lives in the state for a specific period of time, such as 183 days, South Carolina does not have a minimum time that must be spent in the state to be presumed a South Carolina resident for individual income tax purposes.' Residency turns entirely on domicile. |
| 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. | S.C. Code § 12-6-30(2) defines a resident individual as 'an individual domiciled in this State.' Domicile itself is undefined in the tax code and comes from case law: South Carolina courts (Phillips v. South Carolina Tax Commission, 195 S.C. 472, 12 S.E.2d 13 (1940); Gasque v. Gasque, 246 S.C. 423, 143 S.E.2d 811 (1965); Ravenel v. Dekle, 265 S.C. 364, 218 S.E.2d 521 (1974)) define domicile as the place a person has a true, fixed, and permanent home and principal establishment, to which they intend to return whenever absent. Intent is the most important element, evaluated against conduct: the Department's published Domicile Guide (June 2021) lists non-exhaustive factors grouped as property (deeds, real property, motor vehicles, the 4% assessment ratio), employment and financial (where wages are earned, where taxes are paid, bank account and bill addresses), licenses and registrations (voter registration, driver's license, vehicle registration, professional licenses), family (where spouse and dependents live), and affiliations (civic ties, place of worship, professional service providers). No single factor is dispositive. |
| 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; South Carolina has no statutory day-count test. A nonresident who works in South Carolina or spends winter months there does not automatically become a South Carolina resident, and conversely a domiciled South Carolina resident who is physically absent for months or years remains a resident if they intend to return. |
| Presumptions | None published | Military servicemembers who entered service while domiciled in South Carolina are presumed to remain South Carolina residents for tax purposes unless they affirmatively establish legal residence elsewhere and abandon South Carolina domicile (S.C. Regulation 117-640.2). No general civilian day-count presumption exists. |
| 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 South Carolina Residency
| Action | Agency | Deadline |
|---|---|---|
| Get a South Carolina driver license | South Carolina Department of Motor Vehicles (SCDMV) | within 45 days of establishing residency |
| Title and register vehicles | SCDMV | within 45 days of moving to South Carolina |
| Register to vote | South Carolina Election Commission | at least 30 days before an election to vote in it |
| Apply for the 4% legal-residence property tax assessment ratio | County Assessor | by the county's application deadline (varies; commonly before the first penalty date) |
| Apply for the Homestead Exemption if 65+, disabled, or legally blind | County Auditor's Office | after residing in South Carolina as a permanent home for a full prior calendar year |
Declaration of Domicile
South Carolina has no formal sworn Declaration of Domicile filing like Florida's. Domicile is proven through the totality of conduct and documents described in the Department's own Domicile Guide: property records, employment and financial records, licenses and registrations, family location, and community affiliations, with intent as the controlling factor.
Homestead
Two distinct benefits get conflated under 'homestead' in South Carolina. First, the 4% legal-residence assessment ratio (S.C. Code § 12-43-220(c)) is available to any owner-occupant whose South Carolina home is their domicile, cutting the taxable assessment ratio from the standard 6% to 4%, a substantial and immediate property tax reduction that also functions as strong documentary evidence of domicile in an audit, as shown in Brown and Hodson. Second, the separate Homestead Exemption exempts the first $50,000 of fair market value from tax entirely, but only for owners who are 65+, totally and permanently disabled, or legally blind, and only after a full prior calendar year of South Carolina residency; a qualifying surviving spouse can continue the exemption if they take title within nine months of the qualifying spouse's death and remain unmarried.
Voter Registration
Register online, by mail, or in person through the South Carolina Election Commission; the deadline to register for any given election is 30 days before Election Day (https://scvotes.gov/voters/register-to-vote/).
Vehicle Registration Deadline
45 days
New Resident Tax Traps
Because South Carolina has no day-count test, new residents sometimes wrongly assume residency is delayed until they've physically spent significant time in-state; in fact domicile, and the resulting South Carolina tax obligation on worldwide personal service income, can attach immediately upon actually moving with the intent to stay, even before DMV or voter paperwork catches up. The reverse trap: claiming the 4% legal-residence assessment ratio on a South Carolina property while a family member's tax return or another state's homestead filing shows the true domicile is elsewhere invites the same audit pattern seen in Brown and Hodson.
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
South Carolina Top Rate
6%
Moving from Guam to South Carolina drops the top marginal income tax rate from about 75% to about 6%, a reduction of roughly 69 percentage points.
Withholding Reciprocity
Guam and South Carolina 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 South Carolina 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.
South Carolina
Capital gains: Taxed as South Carolina income; a 44% deduction is generally available against net long-term capital gains for state purposes, which is the state's primary capital-gains relief mechanism rather than a separate lower rate.
Estate or inheritance tax: None. South Carolina has no estate tax and no inheritance tax.
Property tax: South Carolina's owner-occupied primary residence qualifies for the 4% legal-residence assessment ratio under S.C. Code § 12-43-220(c) instead of the standard 6% ratio, a major property tax reduction tied directly to domicile; a separate Homestead Exemption for owners 65+, totally and permanently disabled, or legally blind exempts the first $50,000 of fair market value from tax entirely, but only after residing in South Carolina as a permanent home for a full prior calendar year.
Sales tax: 6% state rate, with local option taxes pushing the average combined state-and-local rate to about 7.49%.
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 South Carolina
South Carolina's large hospital systems (MUSC in Charleston, Prisma Health, McLeod) make it a significant travel-nurse assignment market. Because South Carolina has no day-count residency trigger, a nurse working consecutive South Carolina contracts is not automatically pulled into residency the way they would be in a 183-day state; the exposure runs through South Carolina's domicile test instead, meaning a nurse who buys a home, registers to vote, or otherwise shows intent to make South Carolina permanent can become domiciled regardless of the nominal 'tax home' claimed elsewhere.
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 South Carolina
Charleston and Greenville host minor-league and college sports rather than a major-league franchise, so South Carolina's jock-tax exposure is almost entirely on the visiting-player side: nonresident athletes on teams playing in South Carolina owe apportioned South Carolina tax on the personal-service income allocated to South Carolina duty days, following the state's general rule taxing nonresidents on South Carolina-source personal service income.
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 South Carolina
Because South Carolina runs no day-count test, a snowbird can spend an extended winter in South Carolina without becoming a resident, as long as they do not develop the intent to make South Carolina their permanent home; the Department's own guidance states a nonresident spending winter months in South Carolina does not automatically become a South Carolina resident. The risk flips for someone who buys a South Carolina home, joins clubs, opens local bank accounts, and gradually shifts their center of life there, as in Brown, where the taxpayer was found domiciled in South Carolina despite lacking a South Carolina driver's license or vehicle registration that year.
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 South Carolina
South Carolina has no convenience-of-the-employer rule. A remote worker physically performing work from South Carolina owes South Carolina tax on that personal service income (since South Carolina taxes residents' personal service income regardless of source and nonresidents' South Carolina-source personal service income), and the credit for taxes paid to other states (Code § 12-6-3400) is the mechanism for avoiding double taxation if the employer's home state also asserts a claim.
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 South Carolina
South Carolina follows the federal Servicemembers Civil Relief Act, the Military Spouses Residency Relief Act, and the Veterans Benefits and Transition Act: a servicemember does not lose or acquire South Carolina domicile solely by being present or absent under military orders, and a spouse may elect to use the servicemember's state of residence for tax purposes regardless of when the marriage occurred. Under S.C. Regulation 117-640.2, a servicemember who entered service while domiciled in South Carolina is presumed to remain a South Carolina resident for tax purposes unless they affirmatively establish a new domicile and abandon South Carolina, even if the new state (like Texas or Florida) has no income tax.
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 South Carolina
Charlotte Douglas (just across the North Carolina line) and smaller in-state airports mean some airline crew live in South Carolina while based elsewhere. Federal law (49 U.S.C. § 40116) limits state taxation of air carrier employees to their state of residence and, narrowly, a state where more than 50% of pay is earned; crew domiciled in South Carolina are taxed on personal service income under the state's standard resident rules.
Tools for This Move
Guam to South Carolina 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 South Carolina have a 183-day rule like New York or California?+
No. The South Carolina Department of Revenue states directly that, unlike states with a day-count presumption such as 183 days, South Carolina has no minimum time that must be spent in the state to be presumed a resident. Residency depends entirely on domicile: where your true, fixed, permanent home is and where you intend to return when away.
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.
I bought a house in South Carolina but haven't gotten a South Carolina driver's license or registered to vote yet. Am I still a resident?+
Possibly yes. In F. Abbott Brown v. Charleston County Assessor, the taxpayer was found domiciled in South Carolina for a full year despite having none of those three documents, because the court found his conduct, joining a local club, banking locally, moving into the home with intent to stay, demonstrated domicile regardless of the missing paperwork. The Department's own guidance says intent and conduct control, not any single document.
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.
What's the difference between South Carolina's homestead exemption and the 4% assessment ratio?+
They're two different benefits. The 4% legal-residence assessment ratio applies to any owner-occupant whose South Carolina home is their domicile, cutting the property tax assessment ratio from 6% to 4%, and is available immediately. The Homestead Exemption is narrower: it exempts the first $50,000 of fair market value entirely, but only for owners who are 65 or older, totally and permanently disabled, or legally blind, and only after a full prior calendar year of South Carolina residency.
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.
I moved to Wyoming for a few years and never got a Wyoming driver's license. Did I stay a South Carolina resident?+
Not necessarily. In Floyd v. South Carolina Department of Revenue, a taxpayer who moved to Wyoming without ever obtaining a Wyoming license or registering to vote there was still found to have abandoned South Carolina domicile, because the court credited her testimony that she genuinely intended to build a life in Wyoming. Missing documents hurt your case but are not automatically fatal if your actual conduct and credible intent point elsewhere.
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.
Does Social Security get taxed once I retire in South Carolina?+
No. South Carolina fully exempts Social Security benefits, and on top of that offers a $10,000 per-person retirement income deduction at age 65 and older ($3,000 under 65) that applies to pensions, 401(k)s, and IRA distributions.
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.
How does South Carolina tax my income if I still work remotely for my old employer after moving here?+
South Carolina taxes residents on all personal service income (wages and self-employment earnings from labor) regardless of where it's earned, so your remote wages are taxable in South Carolina once you're domiciled here. If your former state also claims a right to tax the same income, South Carolina's credit for taxes paid to another state (Code § 12-6-3400) prevents double taxation.
Considering the reverse move?
South Carolina to Guam
Moving the other direction is a different fact pattern, not a mirror image: exit risk and establishment mechanics both flip.
View the South Carolina to Guam guideGuam to South Carolina Reading
Reviewed Against 15 Primary Sources
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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