The Document Confusion
When a shipment arrives at your warehouse or stockroom, it usually comes with paperwork. Sometimes it's a single sheet inside the box. Sometimes it's an email attachment. Sometimes it's three different documents that all look similar but serve completely different purposes.
For inventory management, knowing which document to trust — and which one to use for updating your stock levels — is more important than most people realize. Using the wrong document can lead to miscounted inventory, billing disputes, and a lot of wasted time.
Let's break down the four most common shipping documents and what each one is actually for.
Packing List
A packing list describes what is physically in the shipment. It's the document that tells you exactly which items were packed into the box or onto the pallet, along with their quantities.
Key characteristics:
- Lists specific items and quantities in the shipment
- Usually created by the warehouse or fulfillment team
- Does not include prices or payment information
- May include weights, dimensions, and package counts
- Accompanies the physical shipment
The packing list is the gold standard for inventory receiving. It tells you what you should find when you open the boxes. If you're updating inventory based on what you actually received, this is the document you want.
Invoice
An invoice is a billing document. It tells you how much you owe for the goods, the payment terms, and when payment is due.
Key characteristics:
- Includes prices, taxes, discounts, and total amounts
- References payment terms (Net 30, due on receipt, etc.)
- May include items from multiple shipments
- May include items that haven't shipped yet
- Used for accounting and accounts payable
Here's the critical difference: an invoice doesn't necessarily match what was shipped. An invoice might cover items from multiple shipments, include back-ordered items that haven't arrived yet, or reflect different quantities than what was actually packed. Using an invoice to update inventory can lead to counting items you don't physically have.
Delivery Note
A delivery note (also called a goods received note or dispatch note) is similar to a packing list but with a slightly different purpose. It's a confirmation document that the goods were delivered.
Key characteristics:
- Confirms what was delivered to the recipient
- Often requires a signature upon delivery
- Usually matches the packing list closely
- May be generated by the shipping carrier or the supplier
- Sometimes includes condition notes
For inventory purposes, delivery notes are nearly as good as packing lists. They describe what was physically delivered, which is what you need for accurate stock counts.
Purchase Order
A purchase order (PO) is what you send to your supplier when you want to buy something. It's your request, not a confirmation of what was sent.
Key characteristics:
- Created by the buyer, not the seller
- Specifies what you want to order and at what price
- Does not confirm what was actually shipped
- May include items that are out of stock or discontinued
- Used as a reference throughout the procurement process
Purchase orders are useful for checking that you received what you ordered, but they should never be used directly for inventory updates. The supplier might have shipped partial quantities, substituted items, or skipped out-of-stock products entirely.
Why This Matters for Inventory Accuracy
The document you use to update your inventory determines how accurate your stock levels are. Here's a simple rule:
Always update inventory based on what you physically received, not what you ordered or what you were billed for.
That means packing lists and delivery notes are your primary sources. Invoices and purchase orders are for financial records and order verification — not for counting stock.
Consider this scenario: you ordered 100 units of a product. The supplier shipped 80 (the rest are back-ordered). The invoice shows 100 because that's the full order amount. If you update your inventory based on the invoice, you'll show 20 items in stock that aren't actually on your shelves. Customers order those items, you can't fulfill the orders, and now you have a customer service problem.
Matching Documents for Verification
Smart inventory teams use multiple documents together for verification:
- Start with the packing list to record what was received.
- Compare against the purchase order to check if the supplier sent everything you ordered.
- Flag discrepancies — missing items, wrong quantities, unexpected substitutions.
- Use the invoice for accounts payable, not for inventory counts.
This three-way matching process catches errors early and keeps both your inventory and your finances accurate.
How ParsePack Handles Document Types
ParsePack is specifically designed to extract inventory data from packing lists and delivery notes — the documents that reflect what was actually shipped and received. When you upload a document, the AI identifies the document type and focuses on extracting the data that matters for inventory: product codes, descriptions, and quantities.
This deliberate focus means you get clean, accurate inventory data rather than financial data mixed with shipping data. You can upload a packing list, review the extracted items, and export a CSV that's ready to import into your e-commerce platform — all based on what's actually in the shipment.
If you receive a document that's actually an invoice or PO rather than a packing list, the extraction still works, but it's worth being aware of the distinction. The quantities on an invoice might not match your physical shipment, so always verify against what you actually received.
The Bottom Line
Understanding your shipping documents isn't just administrative trivia. It directly impacts the accuracy of your inventory, the reliability of your online store, and ultimately your customers' experience. Use packing lists for inventory, invoices for accounting, and purchase orders for procurement tracking — and your stock levels will stay accurate.