NC Income Tax

North Carolina Individual Income Tax Skill — Self-Employed / Sole Proprietor

Scope. This skill covers North Carolina Form D-400 (Individual Income Tax Return) for full-year NC residents who are sole proprietors or single-member LLC owners. Tax year 2025 (returns filed in 2026). North Carolina uses a flat income tax rate.

Quality tier. Q3 — AI-drafted, not independently verified. All outputs must be reviewed by a qualified tax professional before filing.

Section 1: Metadata

Metadata table

Field	Value
Tax type	Individual income tax
Jurisdiction	North Carolina (US-NC)
Tax year	2025 (filed 2026)
Primary form	Form D-400
Supporting schedules	D-400 Schedule S (Additions/Deductions), D-400TC (Tax Credits), D-400 Schedule A (NC Itemized Deductions)
Tax structure	Flat rate
Rate	4.25% (TY 2025)
Filing deadline	April 15, 2026
Extension deadline	October 15, 2026
Tax authority	North Carolina Department of Revenue (NCDOR)
Website	https://www.ncdor.gov
Statute	N.C.G.S. Chapter 105, Article 4

Sources:

• NCDOR, Tax Rate Schedules: https://www.ncdor.gov/taxes-forms/individual-income-tax/tax-rate-schedules
• NCDOR, 2025 D-401 Individual Income Tax Instructions: https://www.ncdor.gov/2025-d-401-individual-income-tax-instructions/open
• Session Law 2023-134 (rate schedule for future years)

Section 2: Quick reference — rates and thresholds

Tax rate

Tax rate schedule (Session Law 2023-134; NCDOR Tax Rate Schedules)

Tax year	Rate	Source
2025	4.25%	Session Law 2023-134; NCDOR Tax Rate Schedules
2026	3.99%	Session Law 2023-134; NCDOR Tax Rate Schedules

North Carolina applies a single flat rate to all taxable income regardless of filing status or income level.

Standard deduction (TY 2025)

Standard deduction table

Filing status	Standard deduction
Single	$12,750
Married filing jointly	$25,500
Married filing separately	$12,750
Head of household	$19,125

Child deduction (TY 2025)

Child deduction table

NC AGI threshold (MFJ)	Deduction per child
Up to $40,000	$3,000
$40,001 – $60,000	$2,500
$60,001 – $80,000	$2,000
$80,001 – $100,000	$1,500
$100,001 – $120,000	$1,000
$120,001 – $140,000	$500
Over $140,000	$0

NC does not have personal exemptions — the child deduction is the only per-dependent benefit.

Local income tax

• Local income tax permitted — North Carolina does not permit local income taxes.

Section 3: How this skill works with the federal return

North Carolina taxable income starts with federal adjusted gross income (AGI) from federal Form 1040, Line 11.

1. Start with federal AGI → D-400, Line 6
2. Add NC additions (Schedule S, Part A) — items NC adds back that were excluded or deducted federally
3. Subtract NC deductions (Schedule S, Part B) — items NC excludes that were included federally
4. Result = NC adjusted gross income
5. Subtract the NC standard deduction (or NC itemized deductions) and child deduction
6. Result = NC taxable income → multiply by 4.25%
7. Subtract credits (D-400TC) → final tax due or refund

Key addition modifications (Schedule S, Part A)

Addition modifications table

Addition	Description
Interest from other states' bonds	Interest income from bonds of states other than NC
Bonus depreciation add-back	NC does not conform to IRC §168(k) bonus depreciation
Section 179 excess	NC limits §179 to $25,000 (does not conform to federal expanded amount)

Key subtraction modifications (Schedule S, Part B)

Subtraction modifications table

Subtraction	Description
US government bond interest	Interest from US Treasury obligations
Retirement benefits (Bailey Settlement)	Certain state/local government retirees exempt per court settlement
Social Security	NC does not tax Social Security benefits

Section 4: Self-employed specific rules

Self-employment income flow

• SE income treatment — Schedule C net profit flows into federal AGI, which flows into NC AGI. NC has no separate self-employment tax — the 4.25% rate applies to all taxable income including self-employment income.

Estimated tax

• Estimated tax payment threshold — $1,000 or more expected liability after withholding and credits

Estimated tax installment due dates

Installment	Due date
1st quarter	April 15
2nd quarter	June 15
3rd quarter	September 15
4th quarter	January 15 (following year)

Form NC-40 is used for estimated tax payments.

Depreciation decoupling

• Bonus depreciation decoupling — NC does not conform to federal bonus depreciation under IRC §168(k). Taxpayers must add back the difference between federal and NC-allowed depreciation on Schedule S. NC follows its own depreciation schedule (generally pre-TCJA rules). This is critical for self-employed taxpayers with significant equipment or vehicle purchases.

Section 179

• NC Section 179 limit — $25,000
• Section 179 excess add-back — NC limits the Section 179 deduction to $25,000 (not the federal expanded amount). Any excess must be added back on Schedule S.

Section 5: Tier 1 rules — deterministic

Tier 1 rules table

Rule ID	Rule	Source
NC-T1-01	NC taxable income = federal AGI ± NC modifications − standard/itemized deduction − child deduction	N.C.G.S. §105-153.4
NC-T1-02	Tax = NC taxable income × 4.25% (TY 2025)	N.C.G.S. §105-153.7; Session Law 2023-134
NC-T1-03	Standard deduction: $12,750 (S), $25,500 (MFJ), $12,750 (MFS), $19,125 (HOH)	N.C.G.S. §105-153.5(a)(1)
NC-T1-04	NC §179 limit = $25,000	N.C.G.S. §105-153.6
NC-T1-05	NC does not conform to IRC §168(k) bonus depreciation	N.C.G.S. §105-130.5B
NC-T1-06	Estimated tax required if expected liability ≥ $1,000	N.C.G.S. §105-163.15
NC-T1-07	NC does not tax Social Security benefits	N.C.G.S. §105-153.5(b)(8)

Section 6: Tier 2 rules — requires judgment

Tier 2 rules table

Rule ID	Situation	Guidance
NC-T2-01	Multi-state income: Taxpayer has income from another state	NC taxes all income of residents; credit for taxes paid to other states available on D-400TC. Allocation requires review.
NC-T2-02	Business vs. hobby determination	NC follows federal hobby loss rules. If IRS disallows Schedule C, NC deductions are also disallowed.
NC-T2-03	IRC conformity date changes	NC references IRC as of a specific date. If federal law changed after NC's conformity date, add-backs or subtractions may be required. Verify conformity date for the tax year.
NC-T2-04	Home office deduction	NC conforms to federal home office deduction rules. Flows through federal AGI. No separate NC adjustment needed.
NC-T2-05	Net operating losses	NC conforms to federal NOL rules with modifications. Post-2017 NOLs limited to 80% of taxable income. Carryforward only (no carryback).

Section 7: Supplier pattern library

Supplier pattern library table

Input needed	Where to find it
Federal AGI	Federal Form 1040, Line 11
NC additions	Schedule S, Part A (computed from federal return)
NC deductions	Schedule S, Part B (computed from federal return)
Standard deduction	Based on filing status
Child deduction	Based on NC AGI and number of qualifying children
Tax credits	D-400TC (credit for taxes paid to other states, child tax credit, etc.)
Estimated tax payments	NC-40 records
NC withholding	W-2 Box 17 / 1099 NC withholding amounts

Section 8: Form mapping

Form D-400 line mapping table

Form D-400 Line	Description	Source
Line 6	Federal adjusted gross income	Federal 1040, Line 11
Line 7	Additions from Schedule S	Schedule S, Part A total
Line 9	Deductions from Schedule S	Schedule S, Part B total
Line 11	NC standard deduction or NC itemized deductions	Computed
Line 13	Child deduction	Based on NC AGI and dependents
Line 14	NC taxable income	Line 6 + Line 7 − Line 9 − Line 11 − Line 13
Line 15	NC income tax	Line 14 × 0.0425
Line 20	Tax credits	D-400TC total
Line 23	NC tax withheld	W-2s / 1099s
Line 25	Estimated tax payments	NC-40 payments

Section 9: Refusal catalogue

Refusal catalogue table

Refusal ID	Trigger	Response
R-NC-01	Part-year or nonresident	"NC part-year and nonresident returns require Schedule PN. This is outside the scope of this skill."
R-NC-02	Corporate or S-corp return	"This skill covers individual income tax only (Form D-400). Corporate returns (CD-405) are not covered."
R-NC-03	Estate or trust return	"NC fiduciary returns (Form D-407) are not covered by this skill."
R-NC-04	Amended return	"NC amended returns (Form D-400X Amended) are not covered."
R-NC-05	Pass-through entity tax	"NC PTET elections are not covered by this skill."

Disclaimer

This skill and its outputs are provided for informational and computational purposes only and do not constitute tax, legal, or financial advice. Open Accountants and its contributors accept no liability for any errors, omissions, or outcomes arising from the use of this skill. All outputs must be reviewed and signed off by a qualified professional before filing or acting upon.

The most up-to-date, verified version of this skill is maintained at openaccountants.com.