Jify Taxes

下載 v2.4.0 安裝 ZIP · 版本紀錄 · 試用／問題回報

免費開源（GPL-2.0-or-later）。已有 WordPress＋WooCommerce 商店即可在測試站開始；主機與其他服務費用另計。

需要逐商品設定稅額計算？把計算基礎看清楚。

適合需要驗證特定 WooCommerce 稅額呈現方式的店家與建站者：針對商品／規格設定稅率，選擇是否扣除整合的商品折扣，以及是否分攤運費。

• 逐商品設定： 選擇哪些商品啟用、使用什麼稅率。
• 查看折扣後基礎： 支援讀取 Jify Discount 提供的商品折扣資料。
• 調整運費計入方式： 可將運費按符合商品的金額比例分攤。

先用一張測試購物車核對

設定商品金額 NT$1,000、可讀取的商品折扣 NT$100、稅率 5%，啟用扣除折扣且不計入運費時：

(1,000 − 100) × 5% = NT$45

這是設定值的運算範例；實際商店應採用的稅務處理，需要依交易情境另行確認。

第一次試用： 在商品／規格啟用 Jify 稅金，設定稅率，分別比較無折扣、有折扣與含運費的結果。

此外掛將計算結果呈現為「稅金」費用列，並抑制原生稅額輸出；不是 WooCommerce 完整原生稅務流程或電子發票系統。需要原生稅務報表、退款或會計串接的商店，請先驗證相容性。

下載後怎麼安裝

1. 下載上方 jify-taxes.zip，不需解壓縮。
2. 到 WordPress 外掛 → 安裝外掛 → 上傳外掛，選取 ZIP 後安裝、啟用。
3. 依上面的第一次試用情境設定；版本需求與完整行為請見下方英文文件。

有想套用的店家情境？告訴我你的設定與預期結果，也歡迎回報第一次安裝卡在哪一步。GitHub Issue 是公開的，請使用測試資料。

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English documentation

Taiwan-oriented tax calculation controls for WooCommerce stores.

Jify Taxes provides product-level tax controls for WooCommerce stores that need Taiwan-specific checkout behavior, including configurable tax rates, tax-base adjustments, discount-aware calculations, shipping allocation, and localized presentation.

This project is an engineering implementation, not legal or accounting advice. Stores should confirm tax treatment with a qualified professional before production use.

The Problem

WooCommerce's global tax engine is flexible, but some stores need a narrower workflow that is easier to reason about for Taiwan operations. Common requirements include:

• Applying a configured tax rate only to selected products or variations.
• Calculating tax after item-level discounts.
• Optionally including shipping in the taxable basis.
• Avoiding duplicate output from WooCommerce's native tax rows.
• Presenting a localized tax label in the cart and checkout.

Jify Taxes implements that workflow as an explicit WooCommerce extension.

Key Features

• Product-level opt-in — enable Jify tax behavior only for selected products or variations.
• Configurable rate — default to 5%, while allowing a per-product or per-variation rate.
• Discount-aware basis — optionally deduct item-level discount amounts before calculating tax.
• Shipping allocation — optionally distribute shipping across taxable line items by line-value proportion.
• Per-item calculation — compute the taxable basis from each eligible cart line.
• Rounded final amount — round the aggregate tax fee before it is added to the cart.
• Native-tax suppression — disable duplicate WooCommerce tax rendering when Jify tax is active.
• Localized presentation — show the resulting charge as 稅金 in checkout totals.

Calculation Model

For each eligible cart item:

basis = line total

if discount deduction is enabled:
    basis -= item discount

if shipping inclusion is enabled:
    basis += allocated shipping

item tax = basis × configured rate

The plugin sums the item-level values, rounds the result, and adds it to the WooCommerce cart as a fee.

Example

Taxable product subtotal: NT$1,000
Item discount:            NT$100
Allocated shipping:       NT$50
Configured rate:          5%

Tax basis: 1,000 - 100 + 50 = NT$950
Calculated tax: 950 × 5% = NT$47.5
Rounded cart fee: NT$48

The exact business and accounting treatment must be reviewed for the store's actual transaction model.

Workflow

Store manager enables Jify Taxes on a product or variation
        ↓
Customer adds eligible items to the cart
        ↓
Plugin suppresses native WooCommerce tax for the Jify path
        ↓
Plugin reads line totals and optional discount data
        ↓
Optional shipping amount is allocated proportionally
        ↓
Tax is calculated per eligible item
        ↓
Aggregate amount is rounded and added as a cart fee

Architecture

The current plugin integrates with:

• WooCommerce product-data tabs.
• Product and variation metadata.
• Cart calculation hooks.
• Session data produced by the Jify Discount workflow.
• WooCommerce tax-status filters.
• Cart tax-total filters.
• Frontend cleanup for native tax rows.

Configuration
├── enable flag
├── tax rate
├── include shipping
└── deduct discount

Runtime calculation
├── eligible-item detection
├── item discount lookup
├── shipping allocation
├── item-level tax calculation
└── aggregate rounding

Presentation
├── native tax suppression
└── localized cart fee

Installation

1. Upload the plugin to /wp-content/plugins/jify-taxes.
2. Activate Jify Taxes from the WordPress Plugins screen.
3. Open a WooCommerce product or variation.
4. Enable the Jify tax option and configure its rate and basis adjustments.
5. Test representative carts before production rollout.

Verification Checklist

Before enabling the plugin on a live store, verify:

• Eligible and ineligible products are separated correctly.
• Product variations inherit or override the intended configuration.
• Discounts reduce the taxable basis only when configured.
• Shipping is included only when configured.
• Mixed carts produce the expected aggregate tax.
• The cart does not display duplicate native WooCommerce tax rows.
• Rounding matches the store's accounting process.
• Refunds, partial refunds, coupons, and order edits are reviewed manually.
• The result has been checked by the store's accountant or tax advisor.

Current Status

• Stable version: 2.4.0.
• The implementation supports per-item tax after discount and optional shipping adjustments.
• It is best treated as a region-specific compatibility layer that requires store-level acceptance testing.
• The current implementation is compact and centralized; future maintenance can separate configuration, calculation, and presentation concerns.

Known Limitations

• This repository does not provide legal, tax, invoice, or accounting certification.
• The current code does not implement a complete electronic-invoice issuance system.
• Checkout themes and third-party plugins may re-render tax rows differently.
• The plugin uses a cart fee to represent the calculated amount rather than WooCommerce's full native tax subsystem.
• Compatibility with refunds, subscriptions, multi-currency, and external accounting systems requires dedicated testing.
• Item discount integration depends on the expected session data being available.

Contributor Opportunities

Useful contribution areas include:

• Extracting the calculation engine into a pure, testable component.
• Adding fixtures for coupons, shipping, mixed rates, and rounding boundaries.
• Improving compatibility with order edits and refunds.
• Adding import and export for product-level tax settings.
• Expanding localization and documentation.
• Building a documented compatibility matrix for WooCommerce versions and checkout implementations.

Related Projects

• Jify Cloud Website
• Jify Shipping
• Jify Discount
• Jify Loyalty

Full product documentation and demos: https://jify.cloud

The canonical WordPress plugin metadata lives in readme.txt.

Ownership

I designed and implemented the product-level configuration, WooCommerce integration, discount-aware tax basis, shipping allocation, localized checkout behavior, and release packaging.

AI coding tools are used in parts of the development workflow. Product decisions, architecture, integration, review, deployment, and acceptance criteria remain my responsibility.

License

GPL-2.0-or-later — see license.txt.