SAT Mexico

An Elixir library that imports reference catalogs from official SAT sources and reads Mexican CFDI XML.

Features

• CFDI XML Parsing: Transform CFDI (Comprobante Fiscal Digital por Internet) invoices from XML format to structured Elixir maps
• ISR Tax Reporting: Generate withholding tax (ISR - Impuesto Sobre la Renta) reports from invoice data
• Batch Processing: Process multiple invoices from directories, including nested XML files and ZIPs
• SAT Compliant: Implements official SAT rounding rules and tax calculations
• Reference Data: Checks official SAT source files and includes catalogs for tax regimes and CFDI usage codes

Check SAT source revisions

Run mix sat.catalogs.check to compare the packaged source manifest with the current links on SAT's Anexo 20 page. It prints one status line per source and returns a non-zero exit status if any source changed or is unreachable. Pass --update to write the new metadata and SHA-256 hashes to priv/sources.json.

Installation

Add sat_mexico to your list of dependencies in mix.exs:

def deps do
  [
    {:sat_mexico, "~> 0.2.0"}
  ]
end

Usage

Parsing CFDI Invoices

# Parse a single XML invoice
{:ok, document} = File.read("path/to/invoice.xml")
{:ok, invoice} = Saxy.parse_string(document, SAT.InvoiceHandler, [])

# Access invoice data
invoice.total          # => "2944.00"
invoice.currency       # => "MXN"
invoice.issuer.tax_id  # => "SAT970701NN3"

Generating ISR Reports

# Process all XML and ZIP files in a directory and its subdirectories
withholdings = SAT.Report.ISR.withholdings("/path/to/invoices")

# Get a detailed summary with SAT rounding applied
result = withholdings
  |> SAT.Report.ISR.withholdings_summarize_detailed()
  |> SAT.Report.ISR.round_withholdings_detailed()

# Print the results
Enum.each(result, fn %{tax_id: tax_id, incoming: incoming, withheld: withheld} ->
  IO.puts("Tax ID: #{tax_id}, Total: #{incoming}, Withheld: #{withheld}")
end)

For more detailed examples, see the ISR Report Guide.

Reference Data

The library includes comprehensive reference data for:

• Tax Regimes: Complete catalog of Mexican tax regimes with validity dates and applicability
• CFDI Usage Codes: Full catalog of CFDI usage codes with descriptions and validity information

Documentation

Full documentation is available at https://hexdocs.pm/sat_mexico.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

This project is licensed under the Apache License 2.0 - see the LICENSE.md file for details.

About

SAT Mexico is maintained by defdo.