Distinguish invoice identifiers from item identifiers

Where the extra work starts

Keep those roles separate so repeated products do not cause the spreadsheet to merge distinct invoices or lose their source.

Upload a representative supplier invoice, inspect its extracted fields and line items beside the PDF, then download Excel. Put the awkward invoice in your trial too: the useful result is less total work after corrections.

A value's appearance does not determine its role. The same digits can legitimately appear as an invoice number on one document and an item code on another.

A practical way to get it right

Inspect the document header for its stated invoice identifier, the table for any line sequence and the item fields for supplier or buyer codes. Record each raw label and value. Where the source does not provide a line identifier, use an internal source-row reference clearly labeled as yours rather than pretending it was printed.

Create a field dictionary naming purpose, source location and preservation rule. Keep numeric-looking identifiers as text. When combining invoices, use a stable internal document reference in addition to the printed invoice number, since a printed number alone may not be globally unique across suppliers or periods.

Review a sample of output rows against the dictionary. Check that a repeated invoice number is carried as document context while item and line identifiers retain their own roles. Do not infer a missing code from a neighboring field merely because both are called ID in a system.

OpenPeppol: Invoice syntax distinguishes the invoice identifier at document level. Preserve it as document context instead of confusing it with a product or row code.

What this looks like on a real task

Synthetic example. The people, references and figures below are invented to demonstrate the method.

All four values can appear on the same output row without being interchangeable. Copy the field, value and role columns and add source page or evidence links. If the PDF lacks a printed line number, an internal value such as DOC-31-page1-row2 should be labeled a source-row reference, not an extracted invoice line ID.

Catch the cases that create rework

A buyer's item identifier and a seller's code may both appear for the same product. Preserve the labels instead of choosing one as the universal SKU without review. Leading zeros can be meaningful in any identifier field; avoid automatic numeric conversion.

If a parser captured the invoice header number in an item column, correct it from the source and inspect other rows for the same mapping error.

OpenPeppol: Item information separately models buyer, seller and standard item identifiers. Keep the source’s identifier role visible rather than collapsing all codes into one unlabeled field.

Decide whether the change is worth keeping

Ask a colleague to identify the document and exact source row from any exported record. They should be able to distinguish printed identifiers from internal references and explain which field supports each lookup. Keep the dictionary with the handoff so a later merge or import cannot silently redefine the meaning of ID.