You Live in Fort Mill and Work in Charlotte. Why Do You File Two State Returns?

2026-10-16 · RKube Services

Live in South Carolina and work in North Carolina? How the NC nonresident D-400 and Schedule PN, the SC1040TC credit and SC withholding fit together for 2026.

Every weekday, thousands of people drive up I-77 from Fort Mill and Rock Hill to jobs in Charlotte. At tax time a lot of them are surprised to find they file two state returns, not one, and some find they've been under-withheld for South Carolina all year.

The good news is that you aren't taxed twice on the same paycheck, as long as you file both returns in the right order and claim the credit South Carolina gives you. This guide walks through the whole setup for 2026: why North Carolina taxes your wages, how the nonresident D-400 and Schedule PN work, how South Carolina's credit for taxes paid to another state is figured on Form SC1040TC, and how to set up withholding so April isn't a shock. The rules come from the NC Department of Revenue and the SC Department of Revenue, with the credit worksheet from the 2025 SC1040TC.

The short version

• North Carolina taxes the wages you earn working in NC, even though you live in SC. Your NC employer withholds NC tax on that pay.
• You file an NC nonresident return (Form D-400 with Schedule PN) if you have NC-source income and your total gross income from all sources meets NC's filing threshold.
• You also file your SC resident return (SC1040). South Carolina taxes all of your income, wherever earned.
• South Carolina gives a credit for the tax you paid NC on the same income, on Form SC1040TC. It's the lesser of the SC tax on that income or the NC tax on it.
• Withholding is the trap. Your NC employer usually withholds only NC tax, so your SC tax can come up short. Fix it with SC estimated payments or extra withholding.
• Due dates for 2026 returns: both the NC D-400 and the SC1040 are due April 15, 2027. The last 2026 SC estimated payment is due January 15, 2027.
• Rates for 2026: NC is a flat 3.99%. SC has two brackets: 1.99% up to $29,999 and 5.21% (minus $966) from $30,000.

Why North Carolina taxes you at all

States tax nonresidents on income earned inside their borders. NCDOR's withholding FAQ puts it plainly: a nonresident employee is subject to NC withholding tax on any part of his wages paid for services performed in North Carolina.

Under North Carolina's definition (G.S. 105-153.3(11)), you're a nonresident if you're domiciled in another state but have income from sources within North Carolina. That's exactly the SC commuter.

The key words are "services performed in this State." What counts is where you physically do the work, not where your employer is based. Days you work from home in South Carolina are SC days, not NC days.

The NC side: D-400 and Schedule PN

Do you have to file?

NCDOR says a nonresident must file Form D-400 if they received NC-source income (including income from a business, trade, profession or occupation carried on in NC, which covers wages for work done in NC) and their total gross income from all sources, inside and outside NC, equals or exceeds the amount in the filing requirements chart.

For tax year 2025, the chart amounts were:

For a full-time Charlotte job, you'll be over the line. Check the 2026 chart in the D-401 instructions when they come out, since amounts can change.

How Schedule PN works

North Carolina doesn't just tax your NC wages at 3.99%. It figures your tax as if all your income were NC income, then taxes only the NC share.

You complete Form D-400 Schedule PN (Part-Year Resident and Nonresident Schedule) to work out the percentage of your total gross income that's subject to NC tax. That percentage goes on Form D-400, line 13. You must attach Schedule PN whenever you enter a taxable percentage there. NCDOR also says to review Schedule PN-1 for NC adjustments that relate to income not listed on Schedule PN.

If all of your income is wages from your Charlotte job, your NC percentage is close to 100%. If you also have SC rental income, a spouse who works in SC, or you work some days from home, the percentage drops.

The NC rate for 2026

North Carolina's individual income tax rate is 3.99% for 2026, down from 4.25% for 2025. The 2026 withholding tables use the same rate.

The SC side: your resident return and the credit

As a South Carolina resident, you report all of your income on the SC1040, including the wages NC already taxed. Then you claim a credit for the NC tax on Form SC1040TC.

Who gets the credit

The SC1040TC says the credit for taxes paid to another state is available to South Carolina residents and part-year residents only. You complete a separate worksheet for each state.

How the credit is figured

The worksheet on the SC1040TC follows these steps:

1. Your South Carolina gross income.
2. The part of line 1 that's also taxed by North Carolina.
3. Line 2 divided by line 1 (the shared percentage).
4. Your South Carolina tax from the SC1040.
5. Tentative credit: line 3 times line 4.
6. Net tax due North Carolina on the income from line 2. The form says not to use withholding from your W-2. This is the tax on your finished D-400, not what your employer took out.
7. Allowable credit: the lesser of line 5 or line 6.

The total goes on SC1040TC line 1 and then flows to your SC1040.

Because the credit is the lesser of the two, you always end up paying at least the higher of the two states' tax on that income. When SC's tax on the shared income is higher than NC's, you pay NC its tax and SC only the difference. When NC's tax is higher, the SC credit wipes out SC tax on that income but you don't get the extra back.

What to attach

Include the SC1040TC and its worksheet, a complete copy of your federal return, and a copy of your NC return with your SC1040. That's why the order matters: finish the D-400 first, then the SC1040.

If NC refunds you later

If North Carolina later refunds or credits part of the tax that generated your SC credit (say you amend your D-400), the SC1040TC says you must file an amended SC return and repay SCDOR within 60 days of receiving the refund or notice of the credit.

What South Carolina changed for 2026

South Carolina's 2026 tax law (Act 110) replaced the old brackets with two: 1.99% on income up to $29,999, and 5.21% of taxable income minus $966 from $30,000 up. It also replaced the federal standard deduction with a new South Carolina Income Adjusted Deduction (SCIAD) that shrinks as federal AGI rises. For a single filer, the SCIAD is $15,000 at AGI up to $40,000 and phases to $0 at $95,000. SCDOR notes that nonresidents prorate it.

For commuters, that means your SC tax on the same wages, and so the gap between your SC tax and your NC credit, can be different for 2026 than it was for 2025. Rerun your numbers for 2026 rather than copying last year's estimate.

Withholding: the part that goes wrong

What your NC employer does

Your Charlotte employer withholds NC income tax on wages for work you do in NC, using the NC-4 you give them. If you don't give one, NCDOR says the employer must withhold as if you're single with no allowances.

One common mix-up: Form NC-4 NRA is not for out-of-state residents. It's for nonresident aliens (people who aren't US citizens and haven't met the green card or substantial presence test). A US citizen living in Fort Mill uses the regular NC-4 (or NC-4 EZ).

What usually doesn't happen

Your NC employer usually isn't withholding South Carolina tax. North Carolina's own rule for its residents working elsewhere shows how states handle this. NCDOR says an NC resident's wages are subject to NC withholding wherever they work, unless the other state requires the employer to withhold for that state. Relief from double withholding is a matter for your home state.

For you, that means the NC tax comes out of each paycheck, and the SC tax that's left over after the credit often doesn't come out at all.

How to fix it

• Ask your employer whether they can also withhold SC tax. Some multi-state employers can; many smaller Charlotte employers can't.
• If not, make SC estimated payments on Form SC1040ES. SCDOR says estimated payments are required if you expect to owe $100 or more. The usual due dates are April 15, June 15, September 15 and January 15.
• The January 15, 2027 payment is your last chance to catch up for 2026.

A worked example

Say you live in Fort Mill and work five days a week at an office in uptown Charlotte. Your 2026 wages are $70,000, and you have no other income. Your NC employer withheld NC tax all year and nothing for SC.

1. NC return first. You file a D-400 with Schedule PN. Since all your income is NC wages, your NC percentage is 100%. After the NC standard deduction for a single filer ($12,750 on the 2025 return; confirm the 2026 amount) and the 3.99% rate, your D-400 shows NC tax of roughly $2,280.
2. SC return next. You report the full $70,000 on your SC1040. A single filer's SCIAD phases down from $15,000 at $40,000 of AGI to zero at $95,000, so at $70,000 it's about $6,820. That leaves SC taxable income of roughly $63,180, and SC tax of about $2,330 (5.21% of taxable income minus $966).
3. SC1040TC. Line 3 is 100% (all your SC income was also taxed by NC). Line 5 is about $2,330. Line 6 is $2,280 from your D-400, not your W-2 withholding. The credit is the lesser: $2,280.
4. What you owe SC: about $50. It's small because NC's tax on the same wages covers almost all of SC's. It's still due with your SC return, so don't assume a zero balance just because NC withheld all year.
5. Next year: if nothing changes, paying a balance this size with the return is fine. Add SC income, like a rental or a side business, and the gap grows quickly; once you expect to owe SC $100 or more, start SC1040ES estimates or ask your employer to withhold SC tax.

These are rounded figures for a single filer with no other adjustments. Your own returns decide the real numbers.

Now change one fact: you work from home in Fort Mill two days a week. Only the three Charlotte days are NC wages, so your employer should withhold NC tax on those days only, your Schedule PN percentage drops to about 60%, your NC tax drops, your SC credit drops with it, and your SC balance due goes up. Keep a log of where you work each day; it's the record both states would ask for.

A checklist for SC residents with NC jobs

1. Give your employer an NC-4 (not an NC-4 NRA unless you're a nonresident alien).
2. Track your work location by day if you split time between NC and home.
3. Ask about SC withholding. If your employer can't do it, set up SC1040ES payments.
4. File your NC D-400 with Schedule PN first.
5. Then file your SC1040 with SC1040TC, using the NC tax from your D-400, not your W-2.
6. Attach a copy of your NC return and your federal return to the SC1040.
7. Rerun your numbers for 2026 under South Carolina's new brackets and SCIAD.
8. Amend SC within 60 days if NC later refunds part of your tax.

Common questions

Do I have to file a North Carolina return if I live in South Carolina? Yes, if you earned income from work in NC and your total gross income meets NC's filing threshold. You file Form D-400 as a nonresident with Schedule PN.

Will I be taxed twice? Not on the same income, if you claim the credit. South Carolina gives a credit on SC1040TC for the NC tax on income both states tax, up to the SC tax on that income.

Which return do I file first? North Carolina. You need the finished NC tax figure for SC1040TC line 6, and you attach a copy of the NC return to your SC1040.

Can I use my W-2 NC withholding for the SC credit? No. The SC1040TC says to use the net tax due North Carolina on your NC return, not withholding from your W-2.

Should I fill out Form NC-4 NRA? Only if you're a nonresident alien for federal tax purposes. A US citizen living in South Carolina uses the regular NC-4.

Does North Carolina tax the days I work from home in South Carolina? NC taxes nonresident wages for services performed in NC, based on where you physically work. Days worked in SC aren't NC-source wages.

Why do I owe South Carolina money every April? Usually because your employer withholds NC tax but not SC tax, and SC's tax on your wages is higher than the NC credit. SC estimated payments on SC1040ES or SC withholding fix it.

This guide is general information about North Carolina and South Carolina individual income tax for tax year 2026, as of October 2026, not legal or tax advice for your situation. Forms and thresholds change each year, so confirm with NCDOR and SCDOR before you file.

RKube Services prepares both returns for SC residents with NC jobs, from Rock Hill and Fort Mill to the Charlotte side of the line: rkubeservices.com.