Invoice mixes an out-of-scope VAT breakdown with breakdowns in other categories
Reported asother_breakdown_presenta breakdown in another category is present
What is wrong
One cac:TaxSubtotal directly under the invoice's own cac:TaxTotal is coded O - out of scope - under the VAT tax scheme, and at least one other breakdown under the same root is in a different category. EN 16931 rule BR-O-11, which ZATCA runs, requires that an invoice carrying an out-of-scope breakdown carry no other kind, so out-of-scope supplies cannot be invoiced alongside taxed, zero-rated or exempt ones. A breakdown whose cac:TaxCategory has no cbc:ID at all also counts as a different category here: an absent code is read as an empty one, which is not the letter O.
What to check in your ERP
The invoice has to be split. Issue the out-of-scope supplies on a document of their own and the rest on another; there is no field to change that will make one document carry both. Before splitting, check whether the out-of-scope category is right at all - it is used far more often than it applies, and a supply that is untaxed but still within the VAT system is zero-rated (Z) or exempt (E), both of which may share an invoice with taxed lines. Check also that every breakdown block your export writes carries its category code, since a block with the code missing is counted as a different category and produces this note on an otherwise wholly out-of-scope document.