What this is about
With reverse charge (§ 13b UStG) the seller’s VAT ID (BT-31) and the buyer’s VAT ID (BT-48) must be on the invoice — only then can the buyer declare the tax.
What to do
Enter the VAT ID of seller and buyer.
Does the error keep coming back?
Then it is not chance but a pipe connected the wrong way. The free 15-minute check finds the spot.
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