Hi all, hoping someone can offer some advice or a moderator can route this to the IBA/Captive team.

We’re unable to press Confirm shipment on multiple Invoice by Amazon (IBA) orders. The buyers have already received their items, but the orders are then auto-cancelled/refunded because the system blocks shipment confirmation.

Error shown:

“Invoice by Amazon orders can only be shipped from locations where you have a valid VAT registration number. Go to ‘Shipping Settings > General Shipping Settings’ to add a valid default delivery address in your VAT-registered country.”

What we’ve already tried :

- Set Default Delivery/Ship-From Address to our GB VAT-registered address.

- Verified Tax Settings (GB VAT active) and Business Address matches VAT country.

- Checked all Shipping Templates to ensure Ship-From is in the VAT-registered country.

- Confirmed IBA enrollment is active in Invoice Settings.

Despite this, the Confirm shipment button remains blocked on these IBA orders.

Account context:

GB marketplace, GB VAT registered.

Orders fulfilled by Merchant (not FBA).

The issue only affects IBA orders; standard orders are fine.

I’ve had no response from seller support or anyone for almost a week despite multiple contacts; each time I phone, I’m told the case is “being investigated,” but there’s no update or action. Unfortunately, this aligns with my long-term experience as a seller (20 years): support outcomes are inconsistent, and I still have cases that have remained open for over a year without a solution. I know sellers have had similar issues, but what was the fix, and how long did it take? Any help or advice would be appreciated because I am getting absolutely nowhere with Amazon.