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BR-02BT-1
input
The invoice number is missing
Every invoice must carry a unique identifier (BT-1).
Only the issuer holds this value: Factlint reports it and never fabricates it. Test your invoice to find out whether it is affected.
Why this error happens
The invoice number belongs to the issuer's own numbering: sequential, without gaps, and binding on their accounts. Nothing in the document makes it possible to reconstruct.
How to fix it
Fill the number in from your invoicing system. Factlint reports it as `needs_input` and never fabricates a default value.