The South Carolina entry, field by field
This is the registry entry our engine applies for tax year 2026, rendered field by field. Where a field is blank in the registry, the row says so rather than filling the gap.
Program flags on this entry
- Wages in state
- Yes
- Contract research in state
- Yes
- Credit for TY2026
- Current credit Yes. Our rules registry carries a current South Carolina research credit for tax year 2026.
- Structure
- Non-incremental: the credit applies to qualified research expenses directly
- Credit rate
- 5% of qualified research expenses
- Base method
- There is no base amount to subtract: the rate applies to South Carolina qualified research expenses directly.
- Statutory liability limitation
- §12-6-3415(B): the credit taken in any one taxable year may not exceed 50% of the taxpayer's REMAINING tax liability after all other credits have been applied - this credit is ordered last and the cap is computed on the post-other-credits residual (TC-18 lines 5-9). Tax liability is outside the study's data; the preparer applies the cap on the return.
- Carryforward
- 10 years
- Carryback
- None recorded
- Refundable?
- Not refundable An affirmative determination in the registry, carried against the statute cited below.
- State form
- SC Sch. TC-18 (credit code 018)
- Statute
- S.C. Code Ann. §12-6-3415
How the South Carolina credit is computed
The South Carolina credit is non-incremental: the rate applies to state qualified research expenses directly, with no base amount subtracted. The registry carries a rate of 5%.
There is no base amount to subtract: the rate applies to South Carolina qualified research expenses directly.
Unused credit carries forward 10 years. Refundability: not refundable.
Ricerca computes the South Carolina figure from the same substantiated expense base as the federal §41 credit, using the registry entry for the tax year claimed and applying the state's own qualification rules to it. Where the registry is silent on a point, the study says so and the position is resolved with the return preparer instead of being assumed.
Claiming it alongside the federal credit
The federal §41 credit comes first. It is computed from the qualified research expenses the study substantiates - wages for qualified services, supplies consumed in research, computer and cloud rental, and the allowable share of contract research - and it lands on Form 6765 with the return.
The South Carolina credit is then computed from that same substantiated base, with the state's own rules applied on top: its rate, its base amount, its caps, and its own view of what counts. Where the work was physically performed matters: state credits generally reach the research done in the state, so the same employee can sit inside one state's base and outside another's.
That is why the allocation work is done once, at the expense level, with the state attribution recorded as it is built rather than reverse-engineered at filing time.
One base, two computations
- 1 Qualify the activities under the four-part test and total the year's QREs.
- 2 Compute the federal §41 credit and file it on Form 6765.
- 3 Apply the South Carolina entry above to the South Carolina share of that base, and file it on SC Sch. TC-18 (credit code 018).
What the registry tells the preparer
These notes travel with the South Carolina entry inside the platform and are reproduced here verbatim, including the registry's own emphasis. They are written for the person signing the return, which is exactly why they belong on a page about the credit.
- ELIGIBILITY GATE: the credit is allowed only to a taxpayer that actually claims the FEDERAL §41 credit for the same taxable year (§12-6-3415(A)) - confirm the federal claim is on the return before taking the state credit.
- QREs take the IRC §41 meaning (the statute incorporates it by reference; TC-18 cites §41(b)) but count only expenses MADE IN South Carolina. South Carolina's IRC conformity is fixed-date (currently the Code as amended through December 31, 2024), so §41 definitions pin to that conformity date, not the live Code.
- Carryforward expiry runs per QRE VINTAGE: unused credit may not be used for a taxable year beginning on or after ten years from the DATE of the qualified research expenses (§12-6-3415(B)) - track carryforward by expense-year vintage, not as a pooled 10-year clock.
- The credit applies against income tax AND the §12-20-50 corporate license fee.
- NO REFUND PROVISION EXISTS. Online summaries sometimes surface a 'fewer than 150 employees / 75% refund / $5M cap' provision - that is the text of H.3592 (2011-2012 session), which died in committee and was never enacted. Do not model it.
Sources
The citations below are carried verbatim on the South Carolina registry entry. They are what the study cites, and what a reviewer can check.
- Statute
- S.C. Code Ann. §12-6-3415
- Form
- SC Sch. TC-18 (credit code 018)
Registry entry version 2024.2, exported from services/study-api/app/engines/rules_engine.py (STATE_RULES_2024 + STATE_RULES_REGIME_OVERRIDES via RulesEngine.get_state_rules) on September 10, 2026. The registry is versioned per state and per tax year: the entry above governs TY2026, and a study for an earlier year is computed under that year's entry instead.