PTET vs. Nonresident Withholding vs. Composite Return

Practitioner reference for the three most-confused entity-level payment mechanisms

The core confusion: All three mechanisms involve the entity making quarterly payments to the state, often labeled "pass-through" something. From the entity's checking account they look identical. But the federal tax treatment, the SALT-cap-workaround status, and the legal framework are completely different. Maine literally titles its nonresident-withholding webpage "Pass-through Entity Taxes" — that page contains zero PTET forms.

The Three Mechanisms Side-by-Side Comparison

PTET (Pass-Through Entity Tax)
Nonresident Withholding
Composite Return
Legal nature
Entity-level income tax. Entity is the taxpayer. Tax imposed on the entity's distributive income.
Prepayment of owner's individual tax. Nonresident owner is the taxpayer. Entity is just collecting/remitting.
Entity files one return on behalf of multiple nonresidents. Each NR is taxpayer for their share.
Required or elective?
ELECTIVE — annually elected, irrevocable for the year. (CT was mandatory through 2023.)
MANDATORY in most states with PIT, unless owner submits exemption affidavit (e.g., IL Form IL-1000-E).
VOLUNTARY/ELECTIVE — usually requires consent from each participating NR owner.
Whom does it cover?
All consenting owners (varies — some states tax all owners' shares automatically once elected).
Nonresidents only. Resident owners file their own state returns.
Nonresidents only, and only those who consent to be in the composite. Other NRs file their own NR returns.
Tax base
Entity's distributive income, by state-source rules. Some states broaden for residents to all income.
NR's share of state-source income only.
NRs' share of state-source income, summed.
Rate
Top individual rate, OR flat state rate, OR graduated brackets — varies by state.
NR's state's tax rate or top individual rate (varies).
Top individual rate (no individual brackets/exemptions — that's the cost of using composite).
⚠ Federal entity deduction?
YES — under IRS Notice 2020-75. Reduces non-separately stated K-1 ordinary income at the entity level.
NO. The payment is treated as the owner's tax payment, not an entity expense.
NO. Same as NR withholding — owner's tax payment, not entity expense.
⚠ Owner federal Schedule A?
NOT NEEDED for the PTET amount — the deduction was already taken at entity level. Owner's K-1 is already lower.
YES — flows to owner's Schedule A, SUBJECT TO $40K/$10K SALT cap. This is the cap problem PTET solves.
YES — same as NR withholding. Subject to owner's SALT cap.
Owner state-level mechanism
Refundable or nonrefundable credit on owner's individual return for owner's share of PTET paid (varies by state).
Withholding credit — same mechanism as W-2 withholding. Owner files NR return (or composite); withholding offsets liability.
Owner does NOT file individual NR return for that state. Composite return covers their NR liability.
⚠ SALT-cap workaround?
YES. The whole point.
NO. Doesn't help with SALT cap at all.
NO. Doesn't help with SALT cap.
Quarterly estimates required?
Yes (most states), forms vary. Underpayment penalties common.
Yes — typically the same quarterly schedule. Forms specific to withholding.
Yes — composite typically uses same quarterly cycle.
Form examples
CA FTB 3893; NY PTET online; NJ PTE-100; OH IT 4738; IL on IL-1065 with box; MD Form 511.
ME Form 941P-ME; WI Form PW-1; CA Form 592-PTE; NY IT-2658; CT mandatory composite reinstated 2024+.
CA Form 540NR composite; ME Form 1040C-ME; OH IT 4708; AZ Form 140NR-Composite.
Owner basis impact
Entity-level deduction reduces non-separately stated income → lower K-1 → lower outside basis increase.
No basis impact at entity level. Treated as a non-deductible distribution to the partner (some states).
Same as withholding — typically treated as distribution to the participating NR.

Federal Tax Cash-Flow — How Each Mechanism Treats $100 of NR Pass-Through Income at 7% State Rate 37% federal bracket assumed

✓ PTET Path (SALT Workaround)

Entity has $100 income → entity pays $7 PTET
↓
Entity deducts $7 federally. K-1 ordinary income to owner = $93
↓
Owner reports $93 on 1040. State tax owed = $7. Owner state credit = $7. Net state owed = $0.
↓
Owner Schedule A SALT for this slice = $0 (PTET already deducted at entity)
Federal tax on $93 × 37% = $34.41
SAVED vs. baseline: $2.59

✗ NR Withholding Path

Entity has $100 income → entity withholds $7 on behalf of NR owner
↓
NO entity-level federal deduction. K-1 ordinary income to owner = $100
↓
Owner reports $100 on 1040. NR state return shows $7 tax liability + $7 withholding credit = $0 due.
↓
Owner Schedule A SALT = $7, but capped at $40K total (OBBBA 2025-2029) — if cap binding, $0 deduction.
Federal tax on $100 × 37% = $37.00
(if SALT cap fully binding)

≈ Composite Return Path

Entity has $100 income → entity files composite, pays $7 on NR's behalf
↓
NO entity-level federal deduction. K-1 ordinary income to owner = $100
↓
Owner reports $100 on 1040. NO individual NR state return needed (composite covers it).
↓
Owner Schedule A SALT = $7, subject to $40K cap. Same federal effect as withholding.
Federal tax on $100 × 37% = $37.00
(if SALT cap fully binding)

How to Identify Which Mechanism a Payment Is Decision Questions

Q1: Is the payment based on ALL participating owners' income, or only nonresidents' shares?
All consenting/participating owners (regardless of residency) → PTET
Only nonresident owners' shares → Withholding or Composite
Q2: Did the entity make an annual election that's irrevocable for the year?
Yes — formal election made (often with election form, deadline, irrevocability) → likely PTET or Composite
No election — just paying because we have NR owners → NR Withholding (mandatory by default)
Q3: Does the owner still need to file an individual NR return in that state?
YES — and they get a state credit for the entity payment → PTET or NR Withholding
NO — entity payment is the owner's full filing → Composite Return
Q4: Look at the form number / portal name — what's the controlling instruction?
Form says "Pass-Through Entity Tax" + references SALT-cap workaround in instructions → PTET
Form says "Withholding" or "Composite" + describes nonresident collection → NR Withholding or Composite
Q5: Was there an entity-level federal tax deduction taken on the 1065/1120S?
Yes — reduces ordinary income on Form 1065/1120S → PTET (per Notice 2020-75)
No — flowed through to owner's K-1 unchanged → Withholding/Composite

Common Confusion Patterns by State Where It Trips Practitioners

ME (Maine)
Maine's MRS website page is titled "Pass-through Entity Taxes - 2025" but contains ONLY withholding forms (941P-ME) and composite forms (1040C-ME). True PTET only enacted 4/10/2026, effective 2026. Pre-2026 ME "PTET payments" were almost certainly Form 941P-ME nonresident withholding.
WI (Wisconsin)
PW-1 nonresident withholding is MANDATORY at 12%/yr underpayment interest, regardless of PTE election. Practitioners often conflate this with PTET. Both have quarterly estimates. PW-1 ≠ PTET. Once PTET is elected, PW account ↔ PTET account transfers possible by written request.
OH (Ohio)
Three distinct forms — and they are mutually exclusive choices per tax year. IT 1140 = mandatory withholding for nonresidents; IT 4708 = composite; IT 4738 = elective PTE tax. Once you file IT 4738 you cannot amend to switch. Disregarded entities NOT eligible for IT 4738.
CT (Connecticut)
Was the only state with mandatory PTET (2018-2023). Now elective for 2024+. Mandatory composite return for nonresidents was REINSTATED for 2024+ if entity is sole source of CT income for NR. Plus 87.5% credit (not 100%) on PTET. Three layers of pass-through tax mechanics interacting.
IL (Illinois)
Triple structure: (1) 1.5% Replacement Tax mandatory at entity level (NOT PTET, NOT withholding — third thing); (2) Pass-through withholding mandatory for nonresidents unless IL-1000-E filed; (3) PTE Tax elective at 4.95%. All three can apply simultaneously to the same entity.
CA (California)
Form 592-PTE = nonresident withholding; Form 3893 = PTET payment voucher. Both filed quarterly, both via FTB. Don't mix payment vouchers — money applied to wrong account creates real reconciliation pain. Owner-level treatment differs (PTET = nonrefundable 5-yr CF credit; 592 withholding = refund/credit on owner return).
NY (New York)
NY has BOTH PTET (online via authorized person) AND nonresident withholding (Form IT-2658, mandatory for nonresident partners). PTET election doesn't eliminate IT-2658 obligation in all cases. Plus NYC PTET is a separate election from NY State PTET.
NJ (New Jersey)
BAIT election doesn't eliminate the entity's existing nonresident withholding obligation in all cases. PTE-100 portal handles BAIT; separate withholding accounts may exist. CBT-2553 trap for old S-corps means BAIT eligibility blocked while withholding continues.

State Mechanism Matrix — Which Mechanisms Apply Where All 51 Jurisdictions

State PTET (Elective Income Tax) Nonresident Withholding Composite Return Option Practice Notes

Federal Documentation for Each Mechanism

PTET: IRS Notice 2020-75 (issued 11/9/2020) — entity-level state income taxes paid by partnerships/S-corps on income are deductible by the entity, not subject to the individual SALT cap. State must be specifically structured to qualify (irrevocable annual election, owner credit, etc.).
Nonresident Withholding: §1446 governs federal withholding on foreign partners. STATE NR withholding is creature of state law — federally, the payment is treated as a tax payment by the partner (the partnership is just a collection agent). NOT deductible by the entity under Notice 2020-75. Flows to partner's Schedule A.
Composite Return: Authorized by state law — entity files one consolidated state return on behalf of consenting nonresident owners. Federal treatment same as withholding — partner is the taxpayer; payment is the partner's tax.

Why Practitioners Confuse These

(1) All three involve quarterly state payments by the entity. (2) Some state portals use the same login or payment system for multiple mechanisms. (3) State websites use "pass-through entity" terminology loosely (Maine's withholding page is titled "Pass-through Entity Taxes"). (4) The bookkeeping debit is identical: "State Tax Payment, [Owner Name or Entity]." (5) Some forms have similar numbers (CA 592-PTE for withholding vs. 3893 for PTET).

Bookkeeping Discipline That Helps

For each state with multiple mechanisms in play (CA, NY, NJ, OH, IL, WI, CT — and now ME), maintain SEPARATE general ledger accounts:
• State PTET Payable / State PTET Paid — for entity-level PTET (deductible)
• NR Withholding Payable / NR Withholding Paid — for nonresident withholding (treated as distribution to partner; not deductible)
• Composite Tax Payable / Composite Tax Paid — for composite returns (treated as distribution; not deductible)
This separation prevents the federal deduction error (deducting NR withholding as if it were PTET) and makes K-1 footnote disclosure correct.

Sources & Disclaimer

Compiled from state DOR sources, IRS Notice 2020-75, AICPA SALT TRP, EisnerAmper PTET Update Feb 2026, BerryDunn (Maine), Plante Moran (Ohio), state-specific practitioner guidance. Verify every jurisdiction's current forms and rules before filing. State legislative changes are frequent in this area — re-verify at least annually.