Postcode Shipping Rule calculates exact shipping rates at checkout from the customer's postcode and the SKUs in their cart. Upload each supplier's rate sheet as Excel, map postcodes to zones, and the correct rate is returned for every combination — no flat rates that lose money on remote deliveries. Each supplier gets its own zones, postcodes, and per-SKU rates; mixed carts are summed automatically. Optional product-page estimator shows shipping cost before checkout.

• Per-SKU, per-postcode shipping rates at checkout via carrier-calculated shipping
• Multi-supplier support — separate rate cards, zones, and postcodes per supplier
• Bulk upload rates from Excel — merge or replace, with progress and cancel
• Mixed-cart handling — rates summed correctly across suppliers
• Optional product-page shipping estimator widget (theme app block)