Dated source review
What the review found
All modeled-data thresholds in the tool data model are verified against the originating IRS Notice or Announcement, AAA press release, or AAA 2025 brochure. The statutory, regulatory, precedent, and specific-numeric claims across the public methodology and FAQs trace to their sources. The data-prose mapping check passes: every effective IRS rate period and AAA actual-cost preset the methodology describes is the exact value the tool returns. The intentional absence of AAA_WEIGHTED_AVG_BY_YEAR[2026] is disclosed inline when the fallback triggers.
10 claims
IRS_BUSINESS_RATES_BY_PERIOD['2024-01-01'].cents = 67.0
the tool data model — { year: 2024, cents: 67.0, depreciationCents: 30.0, notice: 'Notice 2024-08', pressRelease: 'IR-2023-239', announced: '2023-12-14', ... }
IRS_BUSINESS_RATES_BY_PERIOD['2024-01-01'].depreciationCents = 30.0
the tool data model — depreciation portion of the 2024 business rate
Used for the FAVR-plan reference table; the calculator widget does not show this constant directly.
IRS_BUSINESS_RATES_BY_PERIOD['2025-01-01'].cents = 70.0
the tool data model — 2025 entry
IRS_BUSINESS_RATES_BY_PERIOD['2025-01-01'].depreciationCents = 33.0
the tool data model — depreciation portion of the 2025 business rate
IRS_BUSINESS_RATES_BY_PERIOD has 72.5¢ for January–June 2026 and 76¢ for July–December 2026
the tool data model — both 2026 effective-period entries
Announcement 2026-11 raises the business rate effective July 1 and leaves the other provisions of Notice 2026-10 unchanged.
Both 2026 IRS_BUSINESS_RATES_BY_PERIOD entries have depreciationCents = 35.0
the tool data model — depreciation portion of the 2026 business rate (up 2¢ from 2025's 33¢)
Verified via Tier-2 alignment across NATP, Grant Thornton, Bloomberg Tax, and Spidell; press release does not break out depreciation portion so secondary-source verification was required.
AAA_WEIGHTED_AVG_BY_YEAR[2024].perMileCents = 82.0 (from $12,297 / 15,000 miles)
the tool data model — 2024 AAA entry
2025 release cited the 2024 figure as the basis for the $719 decline ("$719 decline from 2024") → $11,577 + $720 ≈ $12,297; consistent within rounding.
AAA_WEIGHTED_AVG_BY_YEAR[2025].perMileCents = 77.18 (from $11,577 / 15,000 miles)
the tool data model — 2025 AAA entry
AAA methodology — 5-year ownership horizon, 15,000 mi/yr, 9 vehicle categories, 45 models — confirmed in the press release.
The 2025 AAA vehicle-category total-cost presets are Small Sedan 55.87¢, Medium Sedan 66.37¢, Subcompact SUV 66.11¢, Compact SUV (FWD) 68.53¢, Medium SUV (4WD) 83.89¢, Midsize Pickup 79.11¢, 1/2 Ton Crew-Cab Pickup 98.54¢, Hybrid 63.94¢, and Electric 71.21¢ per mile at 15,000 miles/year.
the tool data model — AAA_2025_VEHICLE_COST_CATEGORIES
The brochure was parsed with pdftotext -layout; values come from the "Total Cost – 15k mi/yr" rows. These are actual-cost estimates for California comparison mode, not reimbursement rates.
AAA_WEIGHTED_AVG_BY_YEAR[2026] === undefined (intentional gap — AAA 2026 not yet published)
the tool data model — comment explains the absence ("2026 intentionally absent — AAA publishes annually in September")
The widget falls back to the AAA 2025 figure when CA mode is on for year 2026 and discloses the fall-back inline ("AAA 2026 not yet published"). When AAA publishes the 2026 report (expected September 2026), AAA_WEIGHTED_AVG_BY_YEAR[2026] will be populated and the fall-back path will deactivate.
3 claims
"26 CFR §1.62-2 — accountable plans require business connection, substantiation within ~60 days, and return of excess within ~120 days."
public methodology page § "Tax treatment — accountable plans"; public page subject FAQ #5
The 60/120-day safe-harbor windows are at §1.62-2(g)(2).
"26 CFR §1.274-5 — Each business-trip mileage entry requires amount, time/place, and business purpose; contemporaneous logs have 'a high degree of credibility.'"
public methodology page § "Tax treatment — accountable plans" + § "What this tool does NOT compute"; public page subject FAQ #7
"Rev. Proc. 2010-51 — FAVR plan framework for high-mileage drivers; 2026 maximum standard automobile cost = $61,700."
public methodology page § "FAVR plans — for high-mileage drivers"; public page subject FAQ #1 and methodology FAQ #6
6 claims
"26 USC §170(i) — Charitable mileage rate is fixed by statute at 14¢/mile; has not changed since 1998; IRS cannot adjust administratively."
public methodology page § "Where the IRS rates come from"; public page subject FAQ #1
"California Labor Code §2802(a) — 'all necessary expenditures or losses' indemnification duty referenced in the §2802 layer panel."
widget.tsx § "California §2802 actual-cost comparison" footer note
"California Labor Code §2802(b) and §2802(c) — 10% interest from date of expense + attorney's fees referenced in widget footer."
widget.tsx § "California §2802 actual-cost comparison" footer + public methodology page (referenced via the article cross-link)
"California Bus. & Prof. Code §17208 — 4-year UCL SOL for §2802 repackaging."
widget.tsx § "California §2802 actual-cost comparison" footer note
3-year §2802 SOL under CCP §338(a) is also referenced; both verified.
"IRC §67(g) — TCJA suspension of miscellaneous itemized deductions, made permanent by OBBBA (2025), effective January 1, 2026."
public methodology page § "Tax treatment — accountable plans"; widget.tsx tax-treatment note; public page subject FAQ #5
"IRC §262 — commuting between home and regular workplace is personal, not deductible."
public methodology page § "What this tool does NOT compute"; public page subject FAQ #6
3 claims
"Gattuso v. Harte-Hanks Shoppers, Inc., 42 Cal.4th 554 (Cal. 2007) — §2802 satisfied by actual-expense, mileage, or lump-sum method; IRS rate is 'presumptively reasonable but rebuttable.'"
public methodology page § "The California §2802 actual-cost comparison"; widget.tsx § "California §2802 actual-cost comparison" footer; public page subject FAQ #4 + methodology FAQ #2
"Commissioner v. Flowers, 326 U.S. 465 (1946) — commuting between home and regular workplace is personal expense, not business; foundational for the commuting carve-out."
widget.tsx footer disclaimer; public methodology page § "What this tool does NOT compute"; public page subject FAQ #6
"Cohan v. Commissioner, 39 F.2d 540 (2d Cir. 1930) — 'Cohan rule' of estimation has been largely supplanted by strict §274(d) substantiation for passenger automobiles."
supporting research notes only; not shown on the public methodology page
Referenced only in supporting research notes; not surfaced in public methodology page or public page. Captured here for traceability; no tool revision required.
1 claim
"Rev. Rul. 99-7 — Travel from home to a temporary work location outside the metro area is deductible business mileage; 'temporary' = realistically expected to last one year or less."
public page subject FAQ #6 (commuting)
4 claims
"2026 IRS medical and qualifying moving mileage rates: 20.5¢/mile for January–June and 23.5¢/mile for July–December."
public page subject FAQ #1
Calculator does not include medical/moving rates in the compute path; they are only mentioned in FAQ for completeness.
"OBBBA §70113(b) — 2026 moving-rate scope expanded to include intelligence-community personnel (in addition to active-duty military)."
public methodology page § "Where the IRS rates come from"
Mentioned in methodology for context; the calculator's scope is business-rate only so the moving-rate expansion doesn't flow into the compute path.
"2026 IRS charitable mileage rate: 14¢/mile (fixed by 26 USC §170(i) since 1998)."
public page subject FAQ #1; public methodology page § "Where the IRS rates come from"
§170(i) sets the statutory floor; no adjustment authority for IRS.
"AAA 2025 weighted average annual cost: $11,577 (across 9 vehicle categories, 45 models, 5-year/15,000-mile horizon)."
public methodology page § "The California §2802 actual-cost comparison" + AAA table
AAA methodology + categories confirmed in press release.
2 claims
"Notice 2026-10 set the January–June 2026 rates, and Announcement 2026-11 changed the business and medical/moving rates effective July 1."
the tool data model, methodology rate table, and subject FAQ #1
The sources establish both effective periods; the calculator does not infer a single calendar-year rate.
"The applicable rate follows when the transportation expense was incurred, so mileage crossing July 1, 2026 must be split."
public methodology page § "Why the travel period matters"
Announcement 2026-11 expressly distinguishes pre-July and post-July expense periods.
33 unique sources cited across the report — click to audit any claim directly against its evidence.
Every claim above links to the source we used. Open any source to compare the wording here with the underlying rule, guidance, court opinion, or product behavior.
If a source has changed or a claim looks wrong, tell us. We would rather correct the page than leave a stale answer online. See how we fact-check.
Clockspot keeps clock-ins, corrections, approvals, and payroll-ready hours connected so owners and managers can review the workweek before payroll.
Want to simplify how your team tracks time? See how Clockspot works.