Tax Calculation Types in ERPNext (Sales & Purchase Taxes)
In ERPNext, the Sales Taxes and Charges and Purchase Taxes and Charges tables include a Type field that determines how a tax or charge is calculated in a transaction.
Each type defines the base on which the tax is applied, enabling flexible and advanced tax structures.
The “Type” field controls the calculation logic of taxes and charges in ERPNext, allowing both simple and complex tax scenarios.
Tax Calculation Types
1. Actual
The Actual type is used for entering a fixed amount directly.
- Does not depend on item value or percentage
- Used for fixed charges like shipping or delivery fees
Example:
- Shipping Charge = ₹500 (fixed)
2. On Net Total
The On Net Total type applies tax on the total value of all items before any other taxes.
- Most commonly used for standard taxes
- Calculated as a percentage of Net Total
Example:
- 18% GST applied on total invoice value
3. On Previous Row Amount
This type calculates tax based on the amount of the previous tax row.
- Used for cascading tax structures
- Depends on a specific previous row number
Example:
- Education Cess calculated on GST amount
4. On Previous Row Total
This type calculates tax based on the cumulative total up to a previous tax row.
- Each row builds on previous tax calculations
- Useful for layered tax systems
Example:
- Tax applied on (Net Total + previous taxes)
When using “Previous Row Amount” or “Previous Row Total”, you must specify the Row Number to define the reference calculation source.
5. On Item Quantity
The On Item Quantity type applies a fixed tax per unit of item quantity.
- Used for per-item charges
- Not dependent on item price
Example:
- ₹10 tax per unit sold
How It Works in Transactions
In Sales Orders, Purchase Orders, and Invoices:
- Each tax row is evaluated based on its Type
- Calculations follow row sequence
- Cumulative totals are used for dependent rows
Key Use Cases
- Simple percentage-based GST or VAT (On Net Total)
- Fixed logistics or handling charges (Actual)
- Cascading tax systems (Previous Row Amount/Total)
- Per-unit regulatory fees (On Item Quantity)
Summary
ERPNext tax calculation types define how taxes and charges are computed in transactions. By supporting fixed, percentage-based, quantity-based, and cascading calculations, the system enables flexible and accurate tax configuration for diverse business requirements.
