Invoice & Document Intake into Your Accounting System

Someone opens each PDF, reads it and keys the same six fields into the accounting system.

Supplier invoices, receipts and delivery notes arrive as attachments in a mailbox. It is high volume, entirely mechanical, and the cost of doing it by hand is already on the payroll.

Every node with its icon, as on the n8n canvasstarts a runa model or a parser, wired into the node above itHover a node for its name and type

• 01Watch Mailbox & Classify

  20 nodes · 20 connections · 5 notes

  watch the mailbox, classify, route

• 02Extraction & Validation

  13 nodes · 12 connections · 4 notes

  the locked schema, the arithmetic check

• 03PO Matching

  12 nodes · 14 connections · 4 notes

  scored matching, four outcomes

• 04Approval Queue

  20 nodes · 18 connections · 4 notes

  the register, a Slack card, a signed callback

• 05Post to Accounting

  13 nodes · 12 connections · 3 notes

  duplicate guard, post, file, notify

The gates, 11 If and Switch nodes, decide whether anything happens next: a countable part of the system, not a claim about it. The 20 sticky notes carry the reasoning on the canvas, at the point it applies.

HoverTap a card to read what it prevents.

• The arithmetic has no human bypass

  The arithmetic has no human bypass

  An approver can clear “no matching PO” or “over the limit”. Nothing clears a number that does not add up, because approving it would not make it correct.

• Scored matching, not first-match

  Scored matching, not first-match

  Supplier name alone scores 60 against a floor of 75, so it must be corroborated by the amount or the date. A PO dated after the invoice scores nothing on date.

• Ambiguity exits as unmatched

  Ambiguity exits as unmatched

  If the top two candidates are within 10 points, a person chooses. A coin toss dressed as a decision is worse than an honest handoff.

• Approvals are signed, and re-read

  Approvals are signed, and re-read

  The webhook checks Slack’s signature, its freshness and that a secret is configured at all. Status is re-read at decision time, because a Slack button stays clickable after it is pressed.

• The duplicate check sits right before the write

  The duplicate check sits right before the write

  Against the ledger, not a local log: the gap between checking and writing is exactly where a double entry happens.

• Built, not yet deployed. Every file imports cleanly; there has been no successful run against a real Xero account yet.
• The accounting system is Xero. QuickBooks means rewriting the posting workflow; the other four are vendor-neutral.
• OCR is not included. A scanned document with no text layer goes to exceptions rather than being guessed at.
• The auto-approve limit (2,500) and the PO tolerance (2%, or 2 currency units) live in the node: editable, not yet configuration.