Keep invoice service periods separate from issue and due dates

Where the extra work starts

Keep them distinct so a usable invoice workbook supports the right period and payment checks without someone reconstructing the dates by hand.

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 date-role map records what the source says. It does not determine accrual timing, tax treatment or whether a payment is due under an agreement; those questions belong to the authorized reviewer.

A practical way to get it right

Inspect the document header, terms and line descriptions for dated statements. Record the raw label, raw date or range, source location and apparent role. If a date has no clear label, mark its role unknown rather than assigning it by position alone.

Separate document-level dates from line-level periods. Use distinct fields for issue date, stated due date, document period start and end, and any line-specific period. Preserve the original format when it is ambiguous, such as 03/04/2026, until the reviewer confirms its interpretation.

Link each line's period to its source occurrence. Do not automatically copy the document period to every line if the source shows exceptions. If a downstream system requires one date, obtain a documented mapping decision rather than erasing the distinctions in the raw register.

OpenPeppol: Invoice syntax distinguishes issue date, due date and document period. Use those separate roles as a mapping aid, not as a claim that every PDF exposes them clearly.

What this looks like on a real task

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

The service period precedes issue and due dates, while line 3 carries different context. Copy the label, value and role columns and add source page references. The example does not tell you which period to post the invoice to; it preserves the evidence needed for a separate professional decision.

Catch the cases that create rework

A filename date or file creation timestamp is not automatically an invoice date. Keep those as file metadata if needed, clearly separate from printed business dates. A month name in a description may describe an item rather than the whole service period, so inspect its scope.

If the export converts ambiguous date strings according to local settings, compare the result with the source before accepting the normalized date.

OpenPeppol: Invoice line period provides separate start and end dates for a line period. Keep line-level period evidence distinct from document-level dates when the source supplies it.

Decide whether the change is worth keeping

Have a reviewer trace each populated date field to its printed label and scope. Leave unknown roles visible and avoid duplicating one value across fields simply to satisfy a spreadsheet schema. Preserve both raw and interpreted dates where normalization is authorized. This gives later users context without embedding an unsupported accounting conclusion in the extraction.