{
 "dataset": {
  "name": "US Federal Tax Constants, Tax Year 2026",
  "description": "A machine-readable reference table of the United States federal tax constants that apply to tax year 2026 for self-employed and 1099 income. Thirty-six constants: the seven ordinary income tax brackets for each filing status, the standard deduction, the Schedule SE self-employment tax rates, the $184,500 social security wage base, the Additional Medicare Tax thresholds, the section 199A qualified-business-income thresholds and phase-in ranges as amended by OBBBA, the three Form 1040-ES safe-harbour tests and the four 2026 payment dates, the Schedule AI annualised-instalment tables restated for 2026 by Pub. 505 Worksheet 2-9, both 2026 business standard mileage rates, the Form 1099-K reporting thresholds and the simplified home-office rate. Every constant carries its value, its jurisdiction, its tax year, the basis on which it is set (indexed, statutory, structural, annual notice or prescribed), the title and URL of the primary IRS, SSA, statutory or Internal Revenue Bulletin document it was read from, and the date that document was retrieved and read. Nothing that could not be verified against a primary document is included. Published as CSV and JSON under CC0 1.0. United States federal law only, tax year 2026 only: no state or city tax, no credits, no tax advice.",
  "url": "https://gettidycents.com/data/us-federal-tax-constants-2026",
  "version": "2026-08-25",
  "license": "https://creativecommons.org/publicdomain/zero/1.0/",
  "license_name": "CC0 1.0 Universal (public domain dedication)",
  "license_note": "The constants themselves are facts drawn from US federal law and from US government publications; facts are not copyrightable and works of the US federal government are not under copyright. CC0 is applied to this compilation so that no doubt attaches to reusing it. Attribution is welcome, not required.",
  "creator": "Tidy Cents",
  "creator_url": "https://gettidycents.com",
  "jurisdiction": "US-federal",
  "country": "US",
  "currency": "USD",
  "tax_year": 2026,
  "temporal_coverage": "2026-01-01/2026-12-31",
  "language": "en",
  "last_verified_on": "2026-08-25",
  "generated_by": "app/scripts/build-tax-dataset.mjs — run `npm run build:dataset` from app/ to regenerate",
  "generated_from": [
   "factory/products/self-employed-tax-engine/model.py",
   "factory/products/online-seller-profit/model.py"
  ],
  "constant_count": 36,
  "verified_count": 36,
  "columns": [
   "constant",
   "group",
   "value",
   "jurisdiction",
   "tax_year",
   "basis",
   "source_document",
   "source_url",
   "verified_on",
   "status",
   "note",
   "source_model"
  ],
  "column_documentation": {
   "constant": "Identifier of the constant, exactly as it is named in the model it comes from.",
   "group": "Editorial grouping used to organise the published table. Assigned by Tidy Cents, not by the models.",
   "value": "The value, as a string. Where one constant covers several filing statuses or periods, the string names each of them; the JSON distribution also carries the expanded table.",
   "jurisdiction": "The body of law the value belongs to. Every row here is US-federal — there is no state or city constant in this dataset.",
   "tax_year": "The tax year the value is correct FOR, which is not always the year printed on the form it was read from.",
   "basis": "Why the value has the value it has, and therefore when it must be re-read. See basis_values.",
   "source_document": "Title of the primary document the value was read out of.",
   "source_url": "URL of that document.",
   "verified_on": "The date the document at source_url was actually retrieved and the value read from it.",
   "status": "VERIFIED means the cited document was loaded in full on verified_on and the value read from it. Nothing else is published.",
   "note": "What the model records about the value: cross-checks, the exact form line, the quoted sentence, or a correction of a figure that circulates incorrectly.",
   "source_model": "Which of the two models the row comes from."
  },
  "basis_values": {
   "indexed": "Inflation-adjusted every year. Must be re-read from the new revenue procedure (or the SSA base page) before any later tax year is modelled.",
   "statutory": "Fixed in the Internal Revenue Code with no inflation adjustment. Changes only if Congress acts.",
   "structural": "A rate, ratio, date rule or form mechanic. Changes only if the IRS redesigns the form.",
   "indexed-from-2027": "Fixed for tax year 2026 but scheduled to start indexing for years beginning after 2026. The value most likely to be silently wrong in a model carried forward.",
   "annual-notice": "Set by the IRS for the year in a notice, and capable of being changed mid-year by a later announcement — as the 2026 business mileage rate was.",
   "prescribed": "A rate prescribed by a revenue procedure and left unchanged since. Not indexed; re-check only if that procedure is superseded."
  },
  "groups": [
   {
    "id": "brackets",
    "name": "Ordinary income tax rate schedules",
    "description": "The seven 2026 brackets, per filing status. Expanded in full in the JSON file and further down this page.",
    "constant_count": 1
   },
   {
    "id": "standard-deduction",
    "name": "Standard deduction",
    "description": "The 2026 basic standard deduction by filing status.",
    "constant_count": 1
   },
   {
    "id": "self-employment-tax",
    "name": "Self-employment tax (Schedule SE, Form 8959)",
    "description": "The rates, the 92.35% factor, the $400 floor, the social security wage base and the Additional Medicare Tax thresholds.",
    "constant_count": 8
   },
   {
    "id": "section-199a",
    "name": "Qualified business income deduction (section 199A)",
    "description": "Thresholds and phase-in ranges as adjusted for 2026, plus the two new minimum-deduction rules added by OBBBA sec. 70105(b).",
    "constant_count": 7
   },
   {
    "id": "estimated-tax",
    "name": "Estimated tax: the safe-harbour tests and the due dates",
    "description": "Form 1040-ES General Rule percentages, the high-income threshold, the $1,000 de minimis and the four 2026 payment dates.",
    "constant_count": 6
   },
   {
    "id": "schedule-ai",
    "name": "Annualised instalment method (Schedule AI / Pub. 505 Worksheet 2-9)",
    "description": "The period ends, annualisation multipliers, applicable percentages and prorated wage-base limits used when income arrives unevenly across the year.",
    "constant_count": 7
   },
   {
    "id": "mileage",
    "name": "Standard mileage rate",
    "description": "2026 has two business rates: one before 1 July and a higher one from 1 July. A single-rate table understates the second half of the year.",
    "constant_count": 2
   },
   {
    "id": "form-1099-k",
    "name": "Form 1099-K reporting thresholds",
    "description": "The thresholds a third-party settlement organisation must exceed before it files, reverted by OBBBA to $20,000 and 200 transactions.",
    "constant_count": 2
   },
   {
    "id": "home-office",
    "name": "Home office, simplified method",
    "description": "The prescribed rate per square foot and the square-footage cap.",
    "constant_count": 2
   }
  ],
  "not_covered": [
   "State and city income tax of any kind. This is United States federal law only.",
   "Tax credits — earned income, child, education, premium tax credit and every other credit.",
   "Payroll tax as an employer files it (Forms 941/940), and W-2 withholding tables.",
   "Corporate, partnership and S-corporation returns; anything that is not an individual return with self-employment income.",
   "Any tax year other than 2026, and any tax act passed after the verification date above.",
   "Platform selling fees, which drift constantly and are not law. They are not part of this dataset."
  ],
  "model_scope_limits": [
   "United States FEDERAL tax only, tax year 2026 only. No state or city income tax, and no other country. A buyer outside the US, or filing for any other year, must not use it.",
   "Computes tax BEFORE credits. No Child Tax Credit, no earned income credit, no premium tax credit, no education or energy credits. A filer with children will owe materially LESS than this engine says. (Cross-checked: PolicyEngine applied a $2,200 Child Tax Credit to fixture f16 that this engine, by design, does not.)",
   "Ordinary rates only. No preferential rate on net capital gain or qualified dividends (Pub. 505 Worksheets 2-7 / 2-10), so a filer with investment income will be overstated.",
   "No Net Investment Income Tax (3.8%) and no Alternative Minimum Tax.",
   "Itemised deductions are taken as a single number. Their own limits are NOT applied: the SALT cap, the 0.5%-of-AGI charitable floor new for 2026, and the section 68 reduction above $384,350 / $640,600 / $768,700 are the filer's problem, not this engine's.",
   "One trade or business. No aggregation (Schedule B, Form 8995-A), no qualified business loss carryforward (Schedule C), no REIT dividends or PTP income, no agricultural or horticultural co-op patron reduction (Schedule D).",
   "UBIA is accepted as an input but the 'qualified property' tests (placed-in-service date, depreciable period, the 60/120/45-day anti-abuse rule) are not applied.",
   "No farmers or fishers (the 66-2/3% substitution), no household employers, no clergy or church employee income, no Schedule SE optional methods, no section 1062 farmland elections, no estates or trusts, no fiscal-year filers, no nonresident aliens, no RRTA compensation.",
   "Does not compute the underpayment PENALTY itself (Form 2210 Part III Section B). It computes what you must PAY to avoid one.",
   "Not tax advice. It reproduces the arithmetic on published IRS forms; it does not decide whether a business is an SSTB, whether the taxpayer materially participates, or what counts as a deductible business expense."
  ],
  "self_check": {
   "self-employed-tax-engine": {
    "assertions_passed": 210,
    "assertions_failed": 0
   },
   "online-seller-profit": {
    "assertions_passed": 319,
    "assertions_failed": 0
   }
  },
  "distribution": [
   {
    "format": "text/csv",
    "url": "https://gettidycents.com/data/us-federal-tax-constants-2026.csv",
    "description": "The 36 constants, one row each, with the twelve columns above."
   },
   {
    "format": "application/json",
    "url": "https://gettidycents.com/data/us-federal-tax-constants-2026.json",
    "description": "The same 36 constants, plus the expanded rate schedules and Schedule AI tables that the summary rows point at."
   }
  ],
  "disclaimer": "This is a reference table, not tax advice. Verify any figure against the linked primary document before relying on it."
 },
 "constants": [
  {
   "constant": "ordinary_brackets_2026",
   "group": "brackets",
   "value": "7 brackets 10/12/22/24/32/35/37 for single, mfj, mfs, hoh (see BRACKETS)",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed",
   "source_document": "Rev. Proc. 2025-32 (2026 inflation adjustments; announced in IR-2025-103), section 4.01 / 4.14 / 4.26, TABLES 1-4",
   "source_url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "cross-checked against the 2026 Tax Rate Schedules in Pub. 505 (2026) p.31; identical",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "standard_deduction_2026",
   "group": "standard-deduction",
   "value": "mfj/qss 32200, hoh 24150, single 16100, mfs 16100",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed",
   "source_document": "Rev. Proc. 2025-32 (2026 inflation adjustments; announced in IR-2025-103), section 4.01 / 4.14 / 4.26 sec. 4.14(1)",
   "source_url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "also printed in Form 1040-ES (2026) p.2 chart; identical",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "additional_medicare_rate",
   "group": "self-employment-tax",
   "value": "0.009",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 8959, Additional Medicare Tax, rev. 2025 — the latest revision published, lines 7/13",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f8959.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "also IRS Tax Topic 560, Additional Medicare Tax at https://www.irs.gov/taxtopics/tc560",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "additional_medicare_thresholds",
   "group": "self-employment-tax",
   "value": "mfj 250000, mfs 125000, single/hoh/qss 200000",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 8959, Additional Medicare Tax, rev. 2025 — the latest revision published, lines 5/9/15",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f8959.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "also Pub. 505 (2026) p.27 table; statutory under IRC 1401(b)(2)(A), NOT indexed",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "medicare_rate",
   "group": "self-employment-tax",
   "value": "0.029",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Schedule SE (Form 1040), rev. 2025 — the latest revision published, line 11",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040sse.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "oasdi_rate",
   "group": "self-employment-tax",
   "value": "0.124",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Schedule SE (Form 1040), rev. 2025 — the latest revision published, line 10",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040sse.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "se_deductible_half",
   "group": "self-employment-tax",
   "value": "0.50",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Schedule SE (Form 1040), rev. 2025 — the latest revision published, line 13",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040sse.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "deduction is 50% of Sch SE line 12 and therefore excludes Additional Medicare Tax, which is not on Schedule SE",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "se_minimum",
   "group": "self-employment-tax",
   "value": "400",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Schedule SE (Form 1040), rev. 2025 — the latest revision published, line 4c",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040sse.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "se_net_earnings_factor",
   "group": "self-employment-tax",
   "value": "0.9235",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Schedule SE (Form 1040), rev. 2025 — the latest revision published, Part I line 4a",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040sse.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "also Instructions for Form 2210 (2025), Schedule AI Line 28",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ss_wage_base_2026",
   "group": "self-employment-tax",
   "value": "184500",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed",
   "source_document": "SSA Office of the Chief Actuary, Contribution and benefit bases, 1937-2026",
   "source_url": "https://www.ssa.gov/oact/cola/cbb.html",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "determination shown at https://www.ssa.gov/oact/cola/cbbdet.html ($60,600 x 69,846.57 / 22,935.42 = $184,548.71, rounded to nearest $300). Independently confirmed by Pub. 505 (2026) Worksheet 2-9 line 34 col (d) = $184,500. 2025 was $176,100.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_minimum_deduction",
   "group": "section-199a",
   "value": "400",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed-from-2027",
   "source_document": "26 U.S.C. 199A as amended by P.L. 119-21 (OBBBA) sec. 70105 subsec. (i)(1)(B)",
   "source_url": "https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section199A&num=0&edition=prelim",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "PRIMARY SOURCE, not a secondary one. Corroborated by Rev. Proc. 2025-32 sec. 3.12 and by Form 1040-ES (2026) p.2 'Changes to QBID'. Not indexed until 2027.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_minimum_qbi_test",
   "group": "section-199a",
   "value": "1000, and the statutory test is 'AT LEAST $1,000', not 'exceeds $1,000'",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed-from-2027",
   "source_document": "26 U.S.C. 199A as amended by P.L. 119-21 (OBBBA) sec. 70105 subsec. (i)(2)(A)",
   "source_url": "https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section199A&num=0&edition=prelim",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "aggregate QBI across all ACTIVE qualified trades or businesses (material participation, IRC 469(h))",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_phasein_top_2026",
   "group": "section-199a",
   "value": "mfj 553500, mfs 276775, all others 276750",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed",
   "source_document": "Rev. Proc. 2025-32 (2026 inflation adjustments; announced in IR-2025-103), section 4.01 / 4.14 / 4.26 sec. 4.26 ('Phase-in range amount')",
   "source_url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "equals threshold + 150000 (joint) / + 75000 (all others), matching IRC 199A(b)(3)(B)(ii)(II) and 199A(d)(3)(B)(ii) as amended by OBBBA sec. 70105(a). The brief's reported 544,600 is wrong.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_phasein_width",
   "group": "section-199a",
   "value": "75000 (150000 joint)",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "26 U.S.C. 199A as amended by P.L. 119-21 (OBBBA) sec. 70105 subsecs. (b)(3)(B)(ii)(II), (d)(3)(B)(ii)",
   "source_url": "https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title26-section199A&num=0&edition=prelim",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "statute read directly; OBBBA substituted these for 50000/100000",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_rate",
   "group": "section-199a",
   "value": "0.20",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 8995-A (2025) line 3 / IRC 199A(a)",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f8995a.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_reduced_by_half_se",
   "group": "section-199a",
   "value": "QBI is reduced by the deductible part of self-employment tax",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "Instructions for Form 8995-A (2025), 'Determining Your Qualified Business Income'",
   "source_url": "https://www.irs.gov/pub/irs-pdf/i8995a.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "'This includes, but isn't limited to, unreimbursed partnership expenses, business interest expense, deductible part of self-employment tax, self-employment health insurance deduction, and contributions to qualified retirement plans.'",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "qbi_thresholds_2026",
   "group": "section-199a",
   "value": "mfj 403500, mfs 201775, all others 201750",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed",
   "source_document": "Rev. Proc. 2025-32 (2026 inflation adjustments; announced in IR-2025-103), section 4.01 / 4.14 / 4.26 sec. 4.26",
   "source_url": "https://www.irs.gov/pub/irs-drop/rp-25-32.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "THE TASK BRIEF'S REPORTED 394,600 IS WRONG FOR 2026 — that is the 2025 MFJ threshold, printed on the 2025 Form 8995-A.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "due_dates_2026",
   "group": "estimated-tax",
   "value": "2026-04-15, 2026-06-15, 2026-09-15, 2027-01-15",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "Form 1040-ES (2026), Estimated Tax for Individuals, 'Payment Due Dates' p.4",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040es.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "also Pub. 505 (2026) Table 2-1. None of the four falls on a weekend or DC legal holiday in 2026, so no shift applies this year.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "est_100_pct_prior_year",
   "group": "estimated-tax",
   "value": "1.00",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 1040-ES (2026), Estimated Tax for Individuals, General Rule 2b",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040es.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "prior-year return must cover all 12 months",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "est_110_pct_high_agi",
   "group": "estimated-tax",
   "value": "1.10 where 2025 AGI > 150000 (75000 if 2026 status is MFS)",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 1040-ES (2026), Estimated Tax for Individuals, 'Higher income taxpayers'",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040es.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "also Pub. 505 (2026) 'Required Annual Payment - Line 12c'",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "est_90_pct_current_year",
   "group": "estimated-tax",
   "value": "0.90",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 1040-ES (2026), Estimated Tax for Individuals, General Rule 2a",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040es.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "est_de_minimis",
   "group": "estimated-tax",
   "value": "1000",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "Form 1040-ES (2026), Estimated Tax for Individuals, General Rule 1",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f1040es.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "Pub. 505 WS 2-1 line 14b applies it to total tax MINUS withholding, i.e. line 11c - line 13, NOT to line 12c",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "weekend_holiday_shift_rule",
   "group": "estimated-tax",
   "value": "if a due date falls on a Saturday, Sunday, or legal holiday, the payment is on time if made on the next day that is not one of those",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, 'Saturday, Sunday, holiday rule'",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "'A legal holiday includes any legal holiday in the District of Columbia' (Instructions for Form 2210 (2025), Reminders). DC's Emancipation Day, April 16, is the one that most often moves the April instalment.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ai_annualisation_multipliers",
   "group": "schedule-ai",
   "value": "4, 2.4, 1.5, 1",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, Worksheet 2-9 lines 2 and 5",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "identical to Form 2210 (2025) Schedule AI lines 2 and 5",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ai_applicable_percentages",
   "group": "schedule-ai",
   "value": "22.5%, 45%, 67.5%, 90%",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, Worksheet 2-9 line 22",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "identical to Form 2210 (2025) Schedule AI line 20",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ai_half_se_divisor",
   "group": "schedule-ai",
   "value": "8, 4.8, 3, 2",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, Worksheet 2-9 lines 42-43",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "This is the line that tells you HOW the deductible half of SE tax enters period AGI: divide the ANNUALISED SE tax (line 41) by 8/4.8/3/2 and subtract the result when figuring line 1. Form 2210's Schedule AI does not spell this out; only Pub. 505 does.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ai_period_end_dates",
   "group": "schedule-ai",
   "value": "3/31/26, 5/31/26, 8/31/26, 12/31/26",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, Worksheet 2-9 column headings",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "same as Form 2210 (2025) Schedule AI with the year advanced. NO 2026 revision of Form 2210 exists; the 2026 figures were taken from Pub. 505 (2026).",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ai_prorated_ss_limits_2026",
   "group": "schedule-ai",
   "value": "46125, 76875, 123000, 184500",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "indexed",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, Worksheet 2-9 line 34",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "2026-specific. Form 2210 (2025) line 29 shows the 2025 equivalents 44025/73375/117400/176100.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "ai_se_annualisation",
   "group": "schedule-ai",
   "value": "OASDI 0.496/0.2976/0.186/0.124; Medicare 0.116/0.0696/0.0435/0.029",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "IRS Publication 505 (2026), Tax Withholding and Estimated Tax, Worksheet 2-9 lines 37 and 39",
   "source_url": "https://www.irs.gov/pub/irs-pdf/p505.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "identical to Form 2210 (2025) Schedule AI lines 32 and 34",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "form_2210_revision_used",
   "group": "schedule-ai",
   "value": "2025 revision (there is no 2026 revision)",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "structural",
   "source_document": "Form 2210, rev. 2025 — the latest revision published; NO 2026 revision exists / Instructions for Form 2210 (2025), rev. Feb 17 2026",
   "source_url": "https://www.irs.gov/pub/irs-pdf/f2210.pdf",
   "verified_on": "2026-08-24",
   "status": "VERIFIED",
   "note": "Checked https://www.irs.gov/forms-pubs/about-form-2210 on 2026-08-24: current revision is 2025; the only 2026-dated item is a 5-MAR-2026 update to the 2025 instructions. So the STRUCTURE here is the 2025 form's; the 2026 DOLLAR VALUES are from Pub. 505 (2026) Worksheet 2-9, which is a 2026 document.",
   "source_model": "factory/products/self-employed-tax-engine/model.py"
  },
  {
   "constant": "MILEAGE_RATE_BUSINESS_H1",
   "group": "mileage",
   "value": "0.725",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "annual-notice",
   "source_document": "IRS Notice 2026-10, 2026-4 I.R.B. 378 (29 Dec 2025) — 2026 business standard mileage rate; applies to miles driven BEFORE 1 July 2026",
   "source_url": "https://www.irs.gov/newsroom/irs-sets-2026-business-standard-mileage-rate-at-725-cents-per-mile-up-25-cents",
   "verified_on": "2026-08-25",
   "status": "VERIFIED",
   "note": "Quoted from the source: “For 2026, the standard mileage rate is 72.5 cents per mile”",
   "source_model": "factory/products/online-seller-profit/model.py"
  },
  {
   "constant": "MILEAGE_RATE_BUSINESS_H2",
   "group": "mileage",
   "value": "0.76",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "annual-notice",
   "source_document": "IRS Announcement 2026-11, 2026-29 I.R.B. 49 (13 Jul 2026), modifying Notice 2026-10 — business rate for miles driven ON OR AFTER 1 Jul 2026",
   "source_url": "https://www.irs.gov/pub/irs-irbs/irb26-29.pdf",
   "verified_on": "2026-08-25",
   "status": "VERIFIED",
   "note": "Quoted from the source: “(1) Business 76 cents per mile ... The standard mileage rates set forth in Notice 2026-10 continue to apply to deductible transportation expenses paid or incurred for business, medical, or moving expense purposes before July 1, 2026”",
   "source_model": "factory/products/online-seller-profit/model.py"
  },
  {
   "constant": "FED_1099K_GROSS_THRESHOLD",
   "group": "form-1099-k",
   "value": "20000",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "IRS IR-2025-107 (23 Oct 2025) — 1099-K threshold FAQs under OBBBA",
   "source_url": "https://irs.gov/newsroom/irs-issues-faqs-on-form-1099-k-threshold-under-the-one-big-beautiful-bill-dollar-limit-reverts-to-20000",
   "verified_on": "2026-08-25",
   "status": "VERIFIED",
   "note": "Quoted from the source: “third party settlement organizations are not required to file Forms 1099-K unless the gross amount of reportable payment transactions to a payee exceeds $20,000 and the number of transactions exceeds 200”",
   "source_model": "factory/products/online-seller-profit/model.py"
  },
  {
   "constant": "FED_1099K_TXN_THRESHOLD",
   "group": "form-1099-k",
   "value": "200",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "statutory",
   "source_document": "IRS IR-2025-107 (23 Oct 2025), same sentence — 'exceeds 200'",
   "source_url": "https://irs.gov/newsroom/irs-issues-faqs-on-form-1099-k-threshold-under-the-one-big-beautiful-bill-dollar-limit-reverts-to-20000",
   "verified_on": "2026-08-25",
   "status": "VERIFIED",
   "note": "Quoted from the source: “and the number of transactions exceeds 200”",
   "source_model": "factory/products/online-seller-profit/model.py"
  },
  {
   "constant": "HOME_OFFICE_MAX_SQFT",
   "group": "home-office",
   "value": "300",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "prescribed",
   "source_document": "Rev. Proc. 2013-13, via IRS Tax Topic 509",
   "source_url": "https://www.irs.gov/taxtopics/tc509",
   "verified_on": "2026-08-25",
   "status": "VERIFIED",
   "note": "Quoted from the source: “up to a maximum of 300 square feet”",
   "source_model": "factory/products/online-seller-profit/model.py"
  },
  {
   "constant": "HOME_OFFICE_RATE",
   "group": "home-office",
   "value": "5",
   "jurisdiction": "US-federal",
   "tax_year": 2026,
   "basis": "prescribed",
   "source_document": "Rev. Proc. 2013-13, via IRS Tax Topic 509 (Business use of home)",
   "source_url": "https://www.irs.gov/taxtopics/tc509",
   "verified_on": "2026-08-25",
   "status": "VERIFIED",
   "note": "Quoted from the source: “prescribed rate of $5 per square foot of the portion of the home used for business (up to a maximum of 300 square feet)”",
   "source_model": "factory/products/online-seller-profit/model.py"
  }
 ],
 "expanded": {
  "filing_statuses": [
   "single",
   "mfj",
   "mfs",
   "hoh",
   "qss"
  ],
  "brackets": {
   "mfj": [
    [
     "0",
     "0",
     "0.10"
    ],
    [
     "24800",
     "2480",
     "0.12"
    ],
    [
     "100800",
     "11600",
     "0.22"
    ],
    [
     "211400",
     "35932",
     "0.24"
    ],
    [
     "403550",
     "82048",
     "0.32"
    ],
    [
     "512450",
     "116896",
     "0.35"
    ],
    [
     "768700",
     "206583.50",
     "0.37"
    ]
   ],
   "hoh": [
    [
     "0",
     "0",
     "0.10"
    ],
    [
     "17700",
     "1770",
     "0.12"
    ],
    [
     "67450",
     "7740",
     "0.22"
    ],
    [
     "105700",
     "16155",
     "0.24"
    ],
    [
     "201750",
     "39207",
     "0.32"
    ],
    [
     "256200",
     "56631",
     "0.35"
    ],
    [
     "640600",
     "191171",
     "0.37"
    ]
   ],
   "single": [
    [
     "0",
     "0",
     "0.10"
    ],
    [
     "12400",
     "1240",
     "0.12"
    ],
    [
     "50400",
     "5800",
     "0.22"
    ],
    [
     "105700",
     "17966",
     "0.24"
    ],
    [
     "201775",
     "41024",
     "0.32"
    ],
    [
     "256225",
     "58448",
     "0.35"
    ],
    [
     "640600",
     "192979.25",
     "0.37"
    ]
   ],
   "mfs": [
    [
     "0",
     "0",
     "0.10"
    ],
    [
     "12400",
     "1240",
     "0.12"
    ],
    [
     "50400",
     "5800",
     "0.22"
    ],
    [
     "105700",
     "17966",
     "0.24"
    ],
    [
     "201775",
     "41024",
     "0.32"
    ],
    [
     "256225",
     "58448",
     "0.35"
    ],
    [
     "384350",
     "103291.75",
     "0.37"
    ]
   ],
   "qss": [
    [
     "0",
     "0",
     "0.10"
    ],
    [
     "24800",
     "2480",
     "0.12"
    ],
    [
     "100800",
     "11600",
     "0.22"
    ],
    [
     "211400",
     "35932",
     "0.24"
    ],
    [
     "403550",
     "82048",
     "0.32"
    ],
    [
     "512450",
     "116896",
     "0.35"
    ],
    [
     "768700",
     "206583.50",
     "0.37"
    ]
   ]
  },
  "standard_deduction": {
   "mfj": "32200",
   "qss": "32200",
   "hoh": "24150",
   "single": "16100",
   "mfs": "16100"
  },
  "additional_medicare_threshold": {
   "mfj": "250000",
   "qss": "200000",
   "mfs": "125000",
   "single": "200000",
   "hoh": "200000"
  },
  "additional_medicare_rate": "0.009",
  "ss_wage_base": "184500",
  "se": {
   "net_earnings_factor": "0.9235",
   "minimum": "400",
   "oasdi_rate": "0.124",
   "medicare_rate": "0.029",
   "deductible_half": "0.50"
  },
  "qbi": {
   "rate": "0.20",
   "threshold": {
    "mfj": "403500",
    "qss": "201750",
    "mfs": "201775",
    "single": "201750",
    "hoh": "201750"
   },
   "phasein_top": {
    "mfj": "553500",
    "qss": "276750",
    "mfs": "276775",
    "single": "276750",
    "hoh": "276750"
   },
   "phasein_width": {
    "mfj": "150000",
    "qss": "75000",
    "mfs": "75000",
    "single": "75000",
    "hoh": "75000"
   },
   "minimum_deduction": "400",
   "minimum_qbi_test": "1000",
   "w2_50pct": "0.50",
   "w2_25pct": "0.25",
   "ubia_pct": "0.025"
  },
  "estimated_tax": {
   "current_year_pct": "0.90",
   "prior_year_pct": "1.00",
   "prior_year_pct_high": "1.10",
   "high_agi_threshold": "150000",
   "high_agi_threshold_mfs": "75000",
   "de_minimis": "1000",
   "due_dates": [
    "2026-04-15",
    "2026-06-15",
    "2026-09-15",
    "2027-01-15"
   ]
  },
  "schedule_ai": {
   "period_end": [
    "2026-03-31",
    "2026-05-31",
    "2026-08-31",
    "2026-12-31"
   ],
   "annualisation": [
    "4",
    "2.4",
    "1.5",
    "1"
   ],
   "applicable_pct": [
    "0.225",
    "0.45",
    "0.675",
    "0.90"
   ],
   "prorated_ss_limit": [
    "46125",
    "76875",
    "123000",
    "184500"
   ],
   "oasdi_annualisation": [
    "0.496",
    "0.2976",
    "0.186",
    "0.124"
   ],
   "medicare_annualisation": [
    "0.116",
    "0.0696",
    "0.0435",
    "0.029"
   ],
   "half_se_divisor": [
    "8",
    "4.8",
    "3",
    "2"
   ]
  },
  "mileage": {
   "rate_before_1_july": "0.725",
   "rate_from_1_july": "0.76",
   "split_date": "2026-07-01"
  }
 }
}