Xero: import invoices with multiple lines

A multi-line Xero invoice is written as one row per line item, and Xero has exactly one way of knowing which rows belong to the same invoice: the InvoiceNumber column repeated, identically, on every one of those rows. Get that number wrong — leave it blank on a continuation row, or repeat it under a second, different customer — and Xero either rejects the file or, worse, imports it exactly as written.

Accounting Import Check runs three checks around that one repeated number, and they are not the same finding wearing different names. documentFieldNotRepeated is a blocker for a header value — ContactName, InvoiceDate or DueDate — left blank on a continuation row that shares its InvoiceNumber with the row above, and it is the one finding this tool offers to fix automatically: filling the document’s own value down its own rows adds no information the file didn't already carry. documentFieldConflict is a blocker for the same header value disagreeing across an invoice’s rows — a different contact name on two lines of the same InvoiceNumber — and it is never offered a fix, because there is no way to tell which value is right from the file alone; get this one wrong and Xero can silently create a second, duplicate contact. documentRowsSplit is a warning, not a blocker, for an invoice number that reappears somewhere else in the file instead of on the very next row, which some importers read as two separate invoices. One honesty note: this engine’s own mapping also expects ContactName, InvoiceDate and DueDate to repeat on every continuation row, which is a stricter check than Xero’s own article states — Xero’s instructions only require the InvoiceNumber to repeat. That extra requirement is recorded rather than narrowed, because there is no vendor sentence either confirming or contradicting it.

Open the file in a spreadsheet program and check that every row sharing one invoice carries the exact same InvoiceNumber, with no stray space or extra character. Fill ContactName, InvoiceDate and DueDate down every continuation row of that invoice by hand, or let the tool below do it — it only ever copies a value the invoice’s own first row already carried. Where two rows under one InvoiceNumber name two different contacts, stop and check your source records rather than guessing; picking the wrong one creates a duplicate customer in Xero silently. Keep every column heading exactly as Xero’s own template spells it — “Don’t delete any columns or change any column headings, as these are needed for the file to import” is Xero’s own instruction, and a renamed heading reads to Xero as a missing column, not a renamed one.