tax-audit

Audit Checks Table

Audit Workflow

Step 1 — Gather Inputs

Load analysis/tax-doc-summary.csv and count documents. Collect the user's federal form values (federal_values dict), state form values (state_values dict), filing status, and list of completed forms. See Input Schema Reference for the exact keys needed.

Step 2 — Run Cross-Check Script

Invoke cross_check.py to verify internal consistency, withholding match, cross-return consistency, and tax bracket verification.

python .claude/skills/tax-audit/scripts/cross_check.py '{"csv_path": "analysis/tax-doc-summary.csv", "federal_values": {...}, "state_values": {...}, "filing_status": "MFJ"}'

Parse the JSON output. Each check returns: check_name, status (pass/fail/warning), expected, actual, difference, and detail.

Step 3 — Run Completeness Check Script

Invoke completeness_check.py to verify document coverage and required forms.

python .claude/skills/tax-audit/scripts/completeness_check.py '{"csv_path": "analysis/tax-doc-summary.csv", "forms_filed": ["1040", "Schedule A", ...], "filing_status": "MFJ"}'

Parse the JSON output. Check document_coverage for unmapped documents, required_forms for missing schedules, and orphaned_documents for unrecognized types.

Step 4 — Manual Pitfall Review

Read docs/KNOWN-PITFALLS.md and walk through each of the 10 pitfalls against the user's values:

1. AGI includes ALL income — Verify AGI accounts for wages + interest + dividends + capital gains + Schedule C, not just W-2 wages. (Source: illinois-il1040-guide.md, Two-Income Subtraction)
2. Math verified through Python — Confirm all computed values came from script output, not manual arithmetic. (Source: CLAUDE.md, Rules)
3. State rules differ from federal — Confirm IL-1040 computes tax on base income minus exemptions at flat 4.95% rate, not on federal taxable income. (Source: illinois-il1040-guide.md, Illinois Tax Rate)
4. Cross-form references match — Verify 1040 Line 7 matches Schedule D Line 21, 1040 Line 8 matches Schedule 1 Line 10, etc. (Source: 1040-line-by-line.md, Income Section)
5. W-2 Box 5 >= Box 1 — For each W-2 in CSV, confirm Medicare wages >= regular wages. (Source: additional-medicare-tax.md, Form 8959 Line-by-Line)
6. SALT cap on Schedule A only — Confirm SALT cap ($40K MFJ) applied to federal Schedule A but NOT to IL-1040 deductions. (Source: salt-deduction-2025.md, Overall SALT Cap)
7. IL-1040 Line 1 = federal AGI — Already checked by cross_check.py (check fed_state_agi_match). (Source: illinois-il1040-guide.md, Line 1)
8. Student loan interest phase-out — If 1098-E exists but MAGI >= $200K (MFJ), deduction must be $0. (Source: student-loan-interest.md, MAGI Phase-Out)
9. QBI = $0 if Schedule C loss — If Schedule C Line 31 is negative, Form 8995 Line 15 must be $0. (Source: self-employment-qbi.md, QBI Loss Carryforward)
10. Additional Medicare Tax threshold — Combined W-2 Box 5 > $250K (MFJ) triggers Form 8959 even if neither spouse individually exceeds $200K. (Source: additional-medicare-tax.md, How Employer Withholding Works)

For each pitfall, determine: PASS (verified correct), WARNING (could not verify — needs user confirmation), or FAIL (confirmed incorrect).

Step 5 — Estimated Payments Check

Ask the user: "Did you make estimated tax payments during the year?"

• If no: Mark this section as N/A
• If yes: Ask for the amounts paid and compare to:
  • 1040 Line 26 (federal estimated payments)
  • IL-1040 Line 23 (state estimated payments, if applicable)
  • Flag any discrepancy as WARNING

Step 6 — Compile Results

Merge all results from Steps 2–5 into the output format below. Apply the verdict logic:

• Any FAIL anywhere → STOP — DO NOT FILE
• Any WARNING (no FAILs) → REVIEW THESE ITEMS
• All PASS → READY TO FILE

Output Template

Present the audit results in this format:

## Tax Audit Report

Audited against `analysis/tax-doc-summary.csv` (N documents, M values).
Filing status: [status]. Forms reviewed: [list].

### 1. Internal Consistency

| Check | Status | Expected | Actual | Diff | Detail |
|-------|--------|----------|--------|------|--------|
| Wages match W-2 | PASS/FAIL | $X | $Y | $Z | ... |
| Interest match 1099-INT | ... | ... | ... | ... | ... |
| Dividends match 1099-DIV | ... | ... | ... | ... | ... |
| Total income sum | ... | ... | ... | ... | ... |
| AGI calculation | ... | ... | ... | ... | ... |
| Taxable income | ... | ... | ... | ... | ... |

### 2. Math Verification

| Check | Status | Expected | Actual | Diff | Detail |
|-------|--------|----------|--------|------|--------|
| Tax bracket verify | PASS/FAIL/WARN | $X | $Y | $Z | ... |

### 3. Withholding Match

| Check | Status | Expected | Actual | Diff | Detail |
|-------|--------|----------|--------|------|--------|
| Federal withholding | ... | ... | ... | ... | ... |
| State withholding | ... | ... | ... | ... | ... |

### 4. Cross-Return Consistency

| Check | Status | Expected | Actual | Diff | Detail |
|-------|--------|----------|--------|------|--------|
| Federal AGI = State AGI | ... | ... | ... | ... | ... |

### 5. Document Completeness

| Document | Type | Status | Maps To |
|----------|------|--------|---------|
| W-2 (Name - Employer) | W-2 | Mapped | 1040, Schedule A |
| ... | ... | ... | ... |

### 6. Missing Forms

| Form | Status | Reason | Filed? |
|------|--------|--------|--------|
| Schedule B | Required | Interest > $1,500 | Yes/No |
| ... | ... | ... | ... |

### 7. Common Mistakes Review

| # | Pitfall | Status | Detail |
|---|---------|--------|--------|
| 1 | AGI includes all income | PASS | Verified: AGI = wages + interest + dividends + ... |
| ... | ... | ... | ... |

### 8. Estimated Payments

| Check | Status | Detail |
|-------|--------|--------|
| Federal estimated (Line 26) | PASS/N/A | ... |
| State estimated (Line 23) | PASS/N/A | ... |

---

### Verdict

**[VERDICT]**

[Summary paragraph]

- Total checks: N
- Passed: N
- Warnings: N
- Failed: N

---
*Disclaimer: This audit assists with tax return preparation. It does not constitute tax advice. Verify all results against source documents. Consult a qualified tax professional for your specific situation.*

Verdict values:

• READY TO FILE — All checks passed. Return appears consistent and complete.
• REVIEW THESE ITEMS — N items need review before filing. See WARNING items above.
• STOP — DO NOT FILE — N critical errors found. Do NOT file until resolved.

Input Schema Reference

federal_values

Collect these key 1040 line values from the user:

state_values

Collect these key IL-1040 line values:

Additional state values are helpful but not required for the core checks.

forms_filed

A list of form names the user has completed. Common values:

["1040", "Schedule A", "Schedule B", "Schedule C", "Schedule D", "Form 8949", "Schedule 1", "Schedule 1-A", "Schedule 2", "Form 8959", "Form 8995", "IL-1040"]

Mandatory Rules

1. Never attempt to reconstruct redacted SSNs or other PII
2. All calculations run through Python scripts — never do arithmetic in natural language
3. Every tax rule must cite a file in reference/curated/ — format: (Source: filename.md, section)
4. If a rule cannot be verified from curated references: "I cannot verify this from provided IRS materials — check IRS.gov"
5. Any saved forms must leave SSN, bank routing, account number, and signature fields blank
6. No personal information stored in skill files

Script Reference

Also available from /tax-cheatsheet (do not modify):

Related Skills

• /tax-prep — Extract document values into CSV (run first)
• /tax-cheatsheet — Line-by-line form filling help (run before this skill)
• /tax-advisor — Next-year tax planning based on this year's data (run after filing)