Database Reference

Product Fee separates reusable fee types from their product and website assignments. Tax treatment can be defined by the fee type and overridden for a specific assignment.

Relationship	Why it matters
`productfee_type` can use one `tax_class`	Provides the default tax treatment for that reusable fee type.
`productfee_product_fee` assigns one fee type to one `catalog_product_entity`	Determines which product receives the fee.
`productfee_product_fee` belongs to one `store_website`	Allows the amount and applicability to differ between websites.
`productfee_product_fee` belongs to one `productfee_type`	Reuses the fee's identity and default behavior across products.
`productfee_product_fee` can use one `tax_class`	Supports assignment-specific tax treatment where required.

Snapshot columns

Fee results are snapshotted onto Magento item tables — quote_item, sales_order_item, sales_invoice_item and sales_creditmemo_item each carry productfee_amount, base_productfee_amount, productfee_tax_amount, base_productfee_tax_amount plus productfee_applied_json and productfee_tax_json snapshots. This keeps historical orders, invoices and refunds accurate even when fee types change later.

Use the fee type and product assignment forms for changes so totals, tax and sales-document behavior remain consistent.