## TL;DR

Freight and tax lines do not match PO merchandise lines; they match PO terms (freight terms, tax jurisdiction). Validate freight against the agreed Incoterms or freight allowance, and validate tax against the ship-to jurisdiction and taxability rules. Tolerance these separately from merchandise, usually with absolute caps.

## Steps

1. Separate merchandise lines from freight/tax lines.
   Expected: Two match streams.
2. Validate freight against PO freight terms or allowance.
   Expected: Terms-based check.
3. Validate tax against jurisdiction and taxability.
   Expected: Rules-based check.
4. Apply separate tolerances with absolute caps.
   Expected: Right-sized control.
5. Route variances with the specific term breached.
   Expected: Targeted exceptions.

## When to use

- Invoices with freight or tax lines
- Landed cost tracking
- Tax compliance on purchases

## When not to use

- Merchandise line matching
- Tax code selection
- Freight audit (post-payment)

## Compatibility

ERP-agnostic.

## Variant phrasings

### freight line PO matching

### tax on invoice vs PO

### shipping charges invoice match

## Root cause

POs authorize goods; freight and tax are consequences of the shipment, governed by terms and law rather than line prices. Matching them to merchandise lines is a category error.

## Edge cases

- Drop shipments change who pays freight; check the terms
- Tax-exempt entities need certificate validation, not tax matching
- Fuel surcharges need the surcharge schedule on file

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_Y0kwwHGrJdRiAvHcZt5omg