Most batching failures come from missing or malformed order data. Work through these in Shopify:
Missing product weight / 0 lb → add a weight and save.
Billing phone under 10 digits → complete the phone number.
Missing, inactive, or mismatched SKU.
Address formatting → street in Line 1, unit/PO in Line 2, valid ZIP, no special characters.
Wrong ZIP for the carrier.
Ship-from location missing a phone → add a phone to the location and sync.
Service not valid for the address (e.g. UPS to a residential address, Saturday delivery to an ineligible state).
International: no valid services / bad customs value → keep customs values to 2 decimals.
International order split into multiple packages → PDQ can't create the customs declaration for an international order with more than one package. On the Assign screen, set Number Of Packages back to 1, save, and batch again. If the order really needs several boxes, contact support.
Tax ID/EIN in the wrong format (e.g. a stray hyphen).
Order on hold in Shopify → release the hold.
Order edited after batching → needs a resync.
💡 If none of these apply, contact support - a few causes (like international EEL/PFC metadata) need us to fix on the shop.