What it means
The delivery details of an invoice line (SpecifiedLineTradeDelivery in the XML) should not contain a ShipFromTradeParty. That element says who or where the goods were shipped from, for example a warehouse. EN 16931 has no field for it.
Why it matters
The check is a warning, so nothing is rejected. Software that reads only the EN 16931 fields does not look for a ship-from party, so the information is usually dropped on the buyer's side. It is worth fixing if the recipient wants a file without warnings, or if the buyer needs to know where the goods came from, because this field will not carry it.
How to fix it
Clear any warehouse or ship-from setting on the lines in your invoicing software, or switch the export to the EN 16931 profile instead of an extended one. If the buyer needs to know where the goods came from, say so in a note on the invoice. If you build the XML yourself, delete the ShipFromTradeParty block from the line's SpecifiedLineTradeDelivery.
The rule as published
ShipFromTradeParty should not be present Where this rule applies
| Rule set | Version |
|---|---|
| EN 16931 (CII) | 1.3.17 |
| XRechnung 3.0 (CII) | 3.0.2 |
| NLCIUS (CII) | 1.0.3.13 |
| France CTC (CII) | 1.4.0-04 |
Check your file
Drop your e-invoice to see whether CII-SR-166 still fails, and which other rules do.