Tax Liability Summary

Purpose

Compute tax liability by summing tax_lines across all completed (and optionally refunded) orders for a specified date range. Groups results by tax rate label and rate percentage. Exports a tax liability summary suitable for accounting review or filing. Read-only — no data is modified.

Prerequisites

• WooCommerce store with REST API enabled (WooCommerce → Settings → Advanced → REST API)
• Consumer Key and Consumer Secret with Read scope
• Store accessible over HTTPS
• WooCommerce tax calculation must be enabled (WooCommerce → Settings → General → Enable taxes)
• Minimum WooCommerce version: 3.5.0

Parameters

Authentication

WooCommerce uses OAuth 1.0a for HTTP and Basic Auth over HTTPS.

For HTTPS stores (recommended):

Authorization: Basic base64(consumer_key:consumer_secret)

For HTTP stores (development only): Use OAuth 1.0a — include oauth_consumer_key, oauth_nonce, oauth_signature, oauth_signature_method=HMAC-SHA1, oauth_timestamp, oauth_version=1.0

Never log or output consumer_key or consumer_secret values.

See docs/AUTHENTICATION.md for full setup instructions.

Safety

Read-only skill — no mutations are executed. Safe to run at any time.

Workflow Steps

Step 1 — Fetch tax classes

GET /wp-json/wc/v3/taxes/classes

Extract: slug, name — used to label tax groups in the output.

Step 2 — Fetch completed orders in date range

GET /wp-json/wc/v3/orders
  ?status=<statuses joined by comma>
  &after=<date_after>T00:00:00Z
  &before=<date_before>T23:59:59Z
  &per_page=100
  &page=1

Extract per order: id, number, date_created, total_tax, tax_lines[].rate_code, tax_lines[].rate_id, tax_lines[].label, tax_lines[].compound, tax_lines[].tax_total, tax_lines[].shipping_tax_total

Paginate until response length < 100.

Step 3 — Fetch refunded orders (if include_refunded: true)

GET /wp-json/wc/v3/orders
  ?status=refunded
  &after=<date_after>T00:00:00Z
  &before=<date_before>T23:59:59Z
  &per_page=100
  &page=1

Extract same fields. These will be subtracted from the totals.

Step 4 — Aggregate tax by group

For each tax_line in each order:

key = tax_line[group_by field]
totals[key].tax_total += tax_line.tax_total
totals[key].shipping_tax += tax_line.shipping_tax_total
totals[key].order_count += 1

If the order is refunded: subtract instead of add.

Step 5 — Compute totals

grand_total_tax = sum of all totals[key].tax_total + shipping_tax

Step 6 — Format and export

API Endpoints Used

GET  /wp-json/wc/v3/taxes/classes   — list tax classes for labeling
GET  /wp-json/wc/v3/orders          — completed orders with date range filter

Pagination Strategy

WooCommerce REST API uses page/per_page pagination (not cursor-based).

Standard pattern:

page = 1
while True:
  response = GET /endpoint?per_page=100&page=page
  process(response)
  if len(response) < 100: break
  page += 1

Maximum per_page is 100 for most endpoints. The X-WP-Total and X-WP-TotalPages response headers report totals. Always read X-WP-TotalPages on the first request to estimate job size.

Session Tracking

Claude MUST emit the following output at each stage. This is mandatory.

STARTUP:

╔══════════════════════════════════════════╗
║  SKILL: woo-tax-liability-summary        ║
║  STORE: <store_url>                      ║
║  TIME:  <ISO-8601 UTC>                   ║
║  MODE:  READ-ONLY                        ║
╚══════════════════════════════════════════╝

PER-OPERATION (emit after each API call batch):

[N/TOTAL] <METHOD> <endpoint> → <result_count> records | params: <key>=<val>

COMPLETION (human format):

╔══════════════════════════════════════════╗
║  COMPLETE: woo-tax-liability-summary     ║
║  RECORDS PROCESSED: <n>                  ║
║  OUTPUT: <filename>                      ║
╚══════════════════════════════════════════╝

COMPLETION (json format):

{
  "skill": "woo-tax-liability-summary",
  "store": "<store_url>",
  "completed_at": "<ISO-8601>",
  "records_processed": <n>,
  "output_file": "<path>",
  "dry_run": false
}

Output Format

Human format summary:

TAX LIABILITY SUMMARY — mystore.com
Period: 2025-01-01 to 2025-03-31 (Q1 2025)
Orders included: 1,284 completed | 89 refunded (subtracted)

  Tax Rate                Rate %   Product Tax   Shipping Tax   Total
  ─────────────────────────────────────────────────────────────────────
  Standard Rate (US-CA)   10.25%   $12,841.22    $1,203.11    $14,044.33
  Reduced Rate             5.00%    $1,204.88       $98.21     $1,303.09
  Zero Rate                0.00%        $0.00        $0.00         $0.00
  ─────────────────────────────────────────────────────────────────────
  TOTAL                            $14,046.10    $1,301.32    $15,347.42

  Net Revenue (excl. tax):   $142,183.51
  Effective Tax Rate:              10.79%

CSV filename: woo-tax-liability-summary_<YYYY-MM-DD>_<YYYY-MM-DD>.csv Columns: rate_code, rate_label, rate_percent, tax_class, order_count, product_tax_total, shipping_tax_total, total_tax, refund_tax_subtracted

Error Handling

Best Practices

• Always specify both date_after and date_before aligned to your accounting period (Q1, month, year).
• Set include_refunded: true (the default) for accurate net tax liability — gross minus refund adjustments.
• Cross-reference with WooCommerce's built-in Tax Report (WooCommerce → Reports → Taxes) for spot-checks.
• For multi-currency stores: all values are in the store's base currency as stored in WooCommerce.
• Provide the CSV to your accountant rather than the raw API data — the summary format maps to common tax filing requirements.