Understanding Header PO vs Line-Level PO

Last updated: June 9, 2026

OpenEnvoy extracts PO numbers at two levels from an invoice: the Header PO (invoice-level) and the Line PO (line-item-level). This article explains the difference between the two, how they interact during matching, and how to update them.

What is the Header PO?

The Header PO is the PO number extracted from the top of the invoice — it represents the primary PO number associated with the entire job. You can view it in the Details tab of the job page under the invoice info section.

Think of the Header PO as the default PO for the invoice. It applies globally to the job and to all invoice lines unless a more specific line-level PO overrides it.

What is the Line PO?

The Line PO is a PO number extracted at the individual line-item level. Some invoices reference different PO numbers on different lines — for example, when a single invoice covers orders from multiple purchase orders.

Line POs are visible in the line items section of the job and in the match results.

How Header PO and Line PO Work Together

OpenEnvoy follows a simple precedence rule:

1. If no Line PO is present → the Header PO is applied to all lines. When the invoice only has a PO number at the header level and no line-level POs are extracted, the system uses the Header PO as the PO reference for every line item during matching.

2. If a Line PO is present → the Line PO takes priority. When an invoice line has its own PO number, that Line PO is used for matching that specific line — the Header PO is not used for that line. This allows invoices that span multiple POs to be matched correctly, with each line going to the right PO.

3. Lines can have a mix. On the same invoice, some lines may have a Line PO while others don't. Lines with a Line PO use it; lines without one fall back to the Header PO.

How to View and Edit PO Numbers

Viewing the Header PO

  • Go to the job page → Details tab → the PO number is shown in the Info table

  • The Header PO also appears in the job header area at the top of the job page

Editing the Header PO

  • Go to the Details tab → click the edit icon (✏) on the Info table → update the PO number field

  • You can also update it from the Fields menu on the job page

  • After editing, submit the job for rematching so the updated PO is used

Viewing the Line PO

  • Line-level PO numbers are visible in the line items section and in the match results for each line

Editing the Line PO

  • Click the edit icon (✏) next to the line item to modify the PO number for that specific line

  • After editing, submit for rematching

Note: Editing PO numbers is only available on Active Jobs. Completed jobs cannot be modified.

Common Scenarios

Scenario 1: Single PO invoice

The invoice has one PO number at the top. No line-level POs are present. The Header PO is applied to all lines during matching.

Scenario 2: Multi-PO invoice

The invoice references different PO numbers on different line items. Each line uses its own Line PO for matching. The Header PO may still be present but is overridden wherever a Line PO exists.

Scenario 3: PO missing from extraction

The PO number is on the invoice but was not extracted (common with low-quality scans or unusual formatting). You can manually add the PO at the header level via the Details tab, or at the line level via the line edit icon. After adding, submit for rematching.

Scenario 4: Header PO extracted but wrong

The extraction picked up an incorrect PO number. Update it in the Details tab and resubmit for matching.

FAQ

Q: The Header PO is correct but one line has the wrong PO. Do I need to change the Header PO? No. Edit only the specific line's PO number using the line edit icon. The Header PO remains unchanged and continues to apply to all other lines without a Line PO.

Q: I added a Line PO to every line. Does the Header PO still matter? For matching purposes, no — each line will use its own Line PO. However, the Header PO is still displayed on the job and may be used for filtering, reporting, and linked job visibility.

Q: The PO number wasn't extracted at all. Where should I add it? If it's the same PO for all lines, add it at the Header level in the Details tab. If different lines have different POs, add them at the line level. In both cases, submit for rematching after updating.

Need help? Contact support@openenvoy.com.