Tax Deduction Finder

Categorizes your expenses for tax deductions across US, UK, AU, and CA tax codes. Designed for freelancers, self-employed individuals, and small business owners who want to maximize legitimate write-offs without hiring an accountant for every receipt. Parses bank statements, CSV exports, or manual entries and maps each expense to the correct tax category with confidence scoring.

Supported Platforms & Integrations

Platform	Integration Type	Features
QuickBooks Online	CSV/QBO export import	Categorized transaction matching, Schedule C mapping
Xero	CSV export import	Expense code alignment, multi-currency support
Mint (Credit Karma)	CSV export import	Auto-category suggestion from existing labels
Wave Accounting	CSV export import	Receipt parsing, income vs expense separation
Apple Numbers / Google Sheets	Manual spreadsheet input	Custom column mapping, formula-ready output
IRS Free File / HMRC Self Assessment	Reference data	Up-to-date deduction categories and limits

When to Use

• Quarterly tax prep: Run through 3 months of expenses before estimated tax payments to find missed deductions
• Year-end filing: Process your full year of expenses before filing Schedule C, SA103, or equivalent
• Receipt audit: Validate that individual expenses are categorized correctly before submission
• Home office calculation: Determine simplified vs actual method deductions for your workspace
• Freelancer project expenses: Separate deductible business expenses from personal spending on mixed-use accounts
• Vehicle mileage tracking: Calculate standard mileage vs actual expense deductions for business driving

Alternatives to Consider

• Full-service bookkeeper: If you have 500+ transactions per month or complex multi-entity structures
• TurboTax / TaxAct software: If you want guided filing with built-in e-file, not just categorization
• CPA consultation: If you have unusual situations like foreign income, trusts, or large capital gains

Quick Start

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skill: tax-deduction-finder
config:
  tax_country: US
  tax_year: 2025
  filing_status: self-employed
  home_office: true
  vehicle_use: true
input:
  source: csv
  file: expenses_2025.csv
  columns:
    date: "Transaction Date"
    amount: "Amount"
    description: "Description"
    category: "Category"

Example Input:

Transaction Date, Amount, Description, Category
2025-01-15, 89.99, Adobe Creative Cloud, Software
2025-01-20, 45.00, Comcast Internet, Utilities
2025-02-01, 1200.00, Co-working Space Monthly, Rent
2025-02-14, 62.50, Client Lunch - Acme Corp, Meals

Example Output:

Tax Deduction Summary (US - Schedule C)
========================================
Line 10 - Commissions: $0.00
Line 17 - Legal/Professional: $0.00
Line 18 - Office Expense: $89.99
  -> Adobe Creative Cloud (100% business use)
Line 20b - Rent (Other): $1,200.00
  -> Co-working Space Monthly
Line 24a - Travel: $0.00
Line 24b - Meals (50%): $31.25
  -> Client Lunch - Acme Corp (50% deductible)
Line 25 - Utilities: $22.50
  -> Comcast Internet (50% home office allocation)

Total Deductions Found: $1,343.74
Estimated Tax Savings (25% bracket): $335.94
Confidence Score: 92%
Items Needing Review: 1 (Internet allocation %)

Advanced Configuration

Country-Specific Settings

US (Schedule C / Schedule SE)

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us_config:
  schedule: C
  quarterly_estimated: true
  se_tax_deduction: true
  qbi_eligible: true
  home_office_method: simplified  # simplified | actual
  vehicle_method: standard_mileage  # standard_mileage | actual_expenses
  mileage_rate: 0.67

UK (Self Assessment SA103)

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uk_config:
  form: SA103
  flat_rate_scheme: false
  vat_registered: false
  allowable_expenses_method: actual
  trading_allowance: 1000

Parameters Reference

Parameter	Type	Default	Description
tax_country	string	US	Tax jurisdiction: US, UK, AU, CA
tax_year	number	2025	Tax year for deduction limits
filing_status	string	self-employed	self-employed, sole-proprietor, partnership, s-corp
home_office	bool	false	Enable home office deduction calc
home_office_sqft	number	0	Dedicated office square footage
home_total_sqft	number	0	Total home square footage
vehicle_use	bool	false	Enable vehicle deduction calc
business_miles	number	0	Annual business miles driven
depreciation	bool	true	Include Section 179 / capital allowances
confidence_threshold	number	0.7	Min confidence to auto-categorize (0-1)
flag_personal	bool	true	Flag likely personal expenses for review
currency	string	USD	Currency code for amounts

Core Concepts

Concept	Description
Tax Category Mapping	Each expense maps to a specific line item on your tax form (e.g., Schedule C Line 18)
Confidence Scoring	AI assigns 0-100% confidence that an expense is deductible; low scores are flagged
Allocation Splitting	Mixed-use expenses (internet, phone) are split by business-use percentage
Depreciation Rules	Capital assets over threshold are depreciated or Section 179 expensed
Audit Risk Flagging	Expenses commonly flagged by tax authorities are highlighted with documentation tips

Expense Flow:

  CSV/Bank Export ──> Parse & Normalize ──> Category Match Engine
                                                  |
                                    ┌─────────────┼─────────────┐
                                    v             v             v
                              High Confidence  Medium       Low/Personal
                              (auto-assign)   (suggest)    (flag review)
                                    |             |             |
                                    v             v             v
                              ┌─────────────────────────────────┐
                              │   Tax Form Line Item Mapping    │
                              │   + Deduction Summary Report    │
                              └─────────────────────────────────┘

Workflow Examples

Scenario 1: Freelance Developer Quarterly Review

Input: 3 months of Chase checking CSV, home office enabled, US Schedule C Process: 247 transactions parsed -> 89 flagged as potential business -> 72 auto-categorized -> 17 flagged for review Output: $4,230 in deductions found, $1,057 estimated tax savings, 3 items need documentation

Scenario 2: UK Contractor Annual Filing

Input: 12 months of Starling Bank export, SA103 form, VAT-registered Process: 1,100+ transactions -> allowable expenses separated -> flat rate vs actual comparison Output: Recommended actual method (saves £1,200 over flat rate), £18,400 total allowable expenses

Scenario 3: Mixed Personal/Business Account Cleanup

Input: Personal Amex CSV with business and personal mixed, confidence threshold 0.8 Process: 500 transactions -> 120 identified as business -> 95 high confidence -> 25 review needed Output: Clean split file with business-only expenses, $6,800 in deductions, personal items excluded

Best Practices

1. Export full statements: Always export complete date ranges rather than filtering beforehand — the tool catches expenses you might manually overlook
2. Set realistic business-use percentages: Internet at 100% business use will raise audit flags; 40-60% is defensible for home offices
3. Run quarterly, not just annually: Catching miscategorized expenses early prevents year-end scrambles and improves estimated tax accuracy
4. Keep receipt documentation: For any expense over $75 (US) or £50 (UK), ensure you have receipt backup — the tool flags these
5. Review low-confidence items carefully: Items scored below 70% often reveal legitimate deductions you would have missed, or personal expenses that slipped through

Common Issues

Issue: CSV column mapping fails Cause: Bank exports use non-standard column headers (e.g., "Memo" instead of "Description") Fix: Use the columns config to manually map your CSV headers to expected fields. Run with --preview first to see detected columns.

Issue: Home office deduction seems too high Cause: Actual method includes mortgage interest, insurance, repairs proportionally — this is correct but may trigger scrutiny Fix: Compare simplified method ($5/sqft, max 300 sqft = $1,500) against actual. Use whichever is appropriate for your situation and documentation level.

Issue: Foreign currency transactions not converting Cause: Multi-currency accounts export in original currency without conversion Fix: Set currency to your filing currency. The tool uses the transaction-date exchange rate from European Central Bank data for conversion.

Privacy & Data Handling

All expense data is processed locally on your machine. No financial data, transaction details, account numbers, or tax information is transmitted to any external service. Bank CSV files are read from your local filesystem and never cached beyond the current session. The tool does not store historical data between runs — each execution is stateless. For additional security, you can pre-strip account numbers from CSV exports before processing. Tax category mappings reference publicly available IRS, HMRC, ATO, and CRA documentation.