Tax Rules

The Tax Rules module lets you automate assignment of GTU codes, JPK_V7 codes, WooCommerce tax classes, categories/tags and custom meta to products using condition/action rules. It runs on product save, on a scheduled cron and manually (Dry Run + Run Now).

Requirements

Polski PRO requires: Polski (free) v1.6.0+, WordPress 6.4+, WooCommerce 8.0+, PHP 8.1+.

How it works

1. Create a rule: name, match mode (all/any), conditions, actions, triggers, priority.
2. The engine evaluates conditions against every product and applies actions when the rule matches.
3. Every rule application is written to the audit log (who/what/when, dry run or live).
4. Triggers:
   • On product save - the rule runs after a product is created or updated.
   • Daily - the rule runs in the nightly cron against the entire catalog.
   • Weekly - runs once per week (WP-Cron).
   • Monthly - runs once per 30 days (WP-Cron).
   • Manual - the rule runs only when you click Run / Dry Run in the admin.

Configuration

Open WooCommerce > Tax Rules and click Add rule.

Rule fields

Field	Description
Name	Human-readable label (e.g. “Books -> GTU_12”).
Group (optional)	Free-form label used for filtering in the list.
Enabled	Toggle a rule off without deleting it.
Match mode	all - every condition must match, any - at least one must match.
Triggers	When the rule runs (save / daily / weekly / monthly / manual).
Priority	Execution order, ascending (default 10).

Conditions

Format: field | operator | value | key (last field optional).

Fields: title, sku, price, regular_price, stock_quantity, stock_status, category, tag, type, attribute, tax_class, meta_field, gtu_code, jpk_v7_code, taxonomy.

Operators: equals, not_equals, contains, not_contains, starts_with, ends_with, gt, gte, lt, lte, in, not_in, is_empty, is_not_empty.

The taxonomy field accepts any custom taxonomy; put the taxonomy slug in key and a comma-separated list of term IDs in value:

taxonomy | in | 12,34,56 | product_brand

Examples:

title | contains | book
price | gte | 100
category | in | 42,56,78
meta_field | equals | yes | _polski_tablet

Actions

Format: action_type | value.

Action	Description	Example
set_gtu_code	Assign a GTU code	set_gtu_code | GTU_06
remove_gtu_code	Remove the GTU code	remove_gtu_code |
set_jpk_v7_code	Assign a JPK_V7 code	set_jpk_v7_code | GTU_12
set_tax_class	Set a WooCommerce tax class	set_tax_class | reduced-rate
add_category / remove_category	Add or remove a category	add_category | 42
add_tag / remove_tag	Add or remove a tag	add_tag | 77
set_meta_field	Set a meta field	set_meta_field | _polski_custom:flag
mark_receipt_with_nip	Flag product as requiring receipt with NIP	mark_receipt_with_nip | 1

Dry run and Audit log

Each rule has Dry run (preview without writing) and Run now (apply to the whole catalog) actions. The Audit log tab shows the last 200 applications with timestamp, rule, product, match flag, dry-run flag and applied actions.

Smart Pickers (editor helper)

At the top of the rule editor the Insert helper panel lets you add condition/action lines without looking up IDs by hand:

• Category - all product_cat terms (Select2). Buttons append category | in | <ID> or add_category | <ID>.
• Tag - same for product_tag.
• Tax class - list of WooCommerce tax classes. Buttons append set_tax_class | <slug> or tax_class | equals | <slug>.
• GTU code - GTU_01 - GTU_13 dropdown. Three buttons: set_gtu_code, set_jpk_v7_code, or condition gtu_code | equals | <CODE>.

The textarea remains the source of truth - pickers only append lines.

Rule groups

Each rule may carry an optional group label. Groups are used only for organizing and filtering rules in the admin; they do not affect execution.

Search and filters

The rules list supports case-insensitive name search, status filter (enabled/disabled), trigger filter and group filter (visible only when groups exist).

Import and export rules

The Import / export tab lets you:

• Export all rules as a portable JSON file (format polski.tax_rules, v1) for backup or migration.
• Import a previously exported JSON file. Imports always append rules (never replace by ID), so you can safely merge rule sets from multiple stores.

WP-CLI

For large catalogs and automation:

# List rules
wp polski tax-rules list
wp polski tax-rules list --format=json

# Dry-run rule #3
wp polski tax-rules run 3 --dry-run

# Apply rule #3 with 100-item batches
wp polski tax-rules run 3 --batch-size=100

# Export rules to a file
wp polski tax-rules export --file=/tmp/rules.json

# Import rules from a file
wp polski tax-rules import /tmp/rules.json

Bulk action on the products list

On the standard WooCommerce products list (wp-admin/edit.php?post_type=product) the Bulk actions dropdown exposes two entries:

• Apply tax rules - runs every enabled rule against the selected products.
• Dry-run tax rules - reports what would change, without writing.

After execution an admin notice shows the number of products processed, rule matches, and changes applied.

Integration

Assigned GTU and JPK_V7 codes are stored as product meta and can be consumed by:

• the invoicing module (Faktura VAT PDF + KSeF)
• JPK_VAT export
• accounting integrations (wFirma, Fakturownia, iFirma)

Limits and performance

• The daily cron processes the catalog in batches of 50 products.
• The audit log is capped at 10,000 rows; older entries are trimmed automatically.
• The engine guards against recursion: a rule will not re-trigger during its own internal product save.

Caution

Always test a new rule with Dry run before running it against the whole catalog. After changing a tax class or JPK code, invoices and exports should be recalculated.