Order Processing
How Tax Calculation Works
The Zamp Tax plugin processes orders through the following steps:
When an order is initiated, the plugin checks if tax calculations are enabled
Confirms the destination address is valid
Customer group tax exemption status is evaluated
Product tax codes are collected for each line item
Real-time Tax Computation
Tax rates are calculated in real-time during checkout:
Cart contents are sent to Zamp API including:
Line items with quantities and amounts
Product tax codes
Shipping address
Customer exemption status
Zamp API returns:
Itemized tax calculations
Applied tax rates
Total tax amount
Note: If tax calculation fails, the system will default to 0% tax rate.
Order Transaction Flow
The transaction process follows this sequence:
Pre-transaction validation:
Verify API connectivity
Check address is in nexus state
Validate product tax codes
Transaction processing:
Calculate tax rates
Apply tax to line items
Generate tax breakdown
Post-transaction actions:
Log transaction details
Store tax calculations
Queue for reporting
Tax Rate Application
Tax rates are applied according to these rules:
Line item tax calculation:
Individual tax rates per product
Based on product tax code
Considers shipping location
Shipping tax calculation:
Separate shipping tax rates
Based on delivery address
Follows state regulations
Exemption handling:
Zero rate for exempt customers
Partial exemptions where applicable
Documentation requirements
Important: Tax calculations require valid product tax codes and customer address information to function correctly.