I have the same problem, had you solved your problem yet? If you had pls show me. Thank you.
Topic summary
Customers reported a checkout error that appeared only after applying a 10% promo code: the shipping step said the order couldn’t be shipped to the entered address, but checkout worked when the code was removed.
Suggested checks included: replicate the customer’s cart and address, ensure items are marked as physical products, verify Shopify Markets regions are active, and contact support if unresolved.
Root cause identified: shipping rates (“shipping templates”) were configured using exact price points (e.g., $3.99 = Free; $7.98 = $4.00). When the discount changed the cart total to a value that didn’t match any exact tier, Shopify couldn’t select a shipping rate, triggering the error.
Resolution: switch to price ranges for shipping rates so discounted totals are covered (e.g., $0–$3.99 = Free; $4.99–$7.98 = $4.00). After updating to ranges, checkout worked with the promo code.
Outcome: confirmed fix by another merchant. Status: resolved. Key takeaway: ensure price-based shipping tiers include ranges that accommodate discounted order totals.