erpclaw-tax_skill

Overview

This skill manages tax templates, tax rules, item tax overrides, withholding and US 1099 compliance for ERPClaw ERP. It provides a pure calculation engine for invoice-time tax math and tools to resolve which tax template applies based on party, state, category or defaults. The skill is local-only, offline, and uses a single SQLite file for data storage.

How this skill works

Create reusable tax templates made of charge lines (on_net_total, on_previous_row_total, actual) and add tax rules that auto-resolve templates by party, group, shipping state or tax category. The calculate-tax action runs a stateless tax calculation (no DB writes) for invoices. Withholding and 1099 actions record withholding entries, apply backup withholding when no W-9 exists, and generate year-end 1099 aggregates.

When to use it

• When setting up sales or purchase tax rates for a company
• When you need auto-resolution of tax templates for invoices by customer or shipping state
• When calculating tax for an invoice without altering the database (real-time quote/invoice flows)
• When recording backup withholding or tracking vendor W-9 status
• When preparing year-end 1099 data for filing or review

Best practices

• Define clear, descriptive template names and mark company defaults where appropriate
• Create tax rules with specific priorities (party > group > state > category > default) and test with resolve-tax-template
• Use item tax templates for exceptions (e.g., tax-exempt food items) instead of ad hoc invoice edits
• Always run calculate-tax to preview tax breakdown before posting invoices; it won’t write to the DB
• Confirm destructive actions: deleting templates, recording withholding entries, and generating 1099 data

Example use cases

• Create a "CA Sales Tax 7.25%" template and add a state rule so invoices to CA customers auto-apply it
• During invoice creation call resolve-tax-template then calculate-tax to present exact tax and totals to the user
• Add an item tax template to exempt a product from sales tax while keeping a general template for other items
• Record withholding entries and generate 1099 data to produce year-end summaries grouped by supplier and form type
• Check a supplier’s withholding details to show W-9 status and whether 24% backup withholding applies