Packing Slips for Business: What to Include, How to Write One, and Common Mistakes

A packing slip is the document inside your shipment that tells the recipient exactly what’s in the box. It’s not an invoice (no prices) and not a shipping label (that’s stuck outside). It’s a simple checklist for the person receiving the order to verify items, quantities, and any special instructions. Get it right, and you reduce returns, improve customer trust, and make your warehouse run smoother.

What to Include on a Packing Slip

Every packing slip needs a few core pieces of information. Miss one, and you risk confusion or a return.

• Order and shipping details: Order ID, shipping method, and tracking number. The Order ID is what ties the slip to the customer’s purchase in your system.
• Customer information: Full delivery address and a contact phone number (not always required, but helpful for delivery issues).
• Itemized list of products: For each item, include the product name, SKU (stock-keeping unit), quantity, and any special handling notes (e.g., “Fragile – handle with care” or “This is a gift”).
• Backordered or missing items: If something is out of stock or delayed, note it clearly. Example: “Item #SKU-102 is backordered and will ship separately.”
• Return information: If you handle returns, include the RMA (Return Merchandise Authorization) number and the return address. Some businesses also add a barcode for the Order ID or Warehouse RMA ID to speed up processing at 3PL facilities.
• Ship-to address: The return address where the package should be sent if there’s a problem. This is different from the customer’s delivery address.

For example, if you run a skincare brand like GlowNest Co., your packing slip for a three-item order would list: “Vitamin C Serum (SKU-VC100) – 1, Hyaluronic Acid Moisturizer (SKU-HA200) – 2, Retinol Night Cream (SKU-RN300) – 1.” No prices, no discount codes.

How to Write a Packing Slip (Step by Step)

You don’t need fancy software. A simple template in your order management system or even a spreadsheet works. Here’s the process:

1. Pull the order data: Start with the Order ID, customer name, and shipping address from your sales platform (Shopify, WooCommerce, etc.).
2. List every item: Write each product’s name, SKU, and quantity. Double-check that the numbers match the order. One common mistake is listing items that were canceled or swapped.
3. Add notes for exceptions: If an item is backordered or packed separately, say so. Don’t assume the customer will figure it out.
4. Include return details: Add your return address and an RMA number if your process requires one. For 3PL warehouses, include a barcode for the Order ID or Warehouse RMA ID.
5. Print and insert: Print the slip on plain paper (no need for expensive stock) and place it inside the box on top of the items. Do not tape it to the outside—that’s what the shipping label is for.

Common Mistakes to Avoid

Even experienced fulfillment teams slip up. Here are the top mistakes and how to fix them.

• Including prices: This is the #1 error. A packing slip is not an invoice. Prices can cause confusion, especially if the customer paid a different amount or received a discount. Keep it to item names, SKUs, and quantities only.
• Using the wrong address: If you print a packing slip with an old return address or a warehouse that doesn’t accept returns, you’ll lose time and money. Always verify the ship-to address matches your current return policy.
• Omitting backordered items: Customers get frustrated when they open a box and something is missing with no explanation. If an item is delayed, list it and say “will ship separately.”
• Mixing packing slips with invoices: Some businesses include an invoice in the same box. That’s fine, but keep them as separate documents. Don’t combine them into one sheet that shows prices and quantities together—it confuses warehouse staff and customers.
• Skipping barcodes for high-volume operations: If you use a 3PL or process hundreds of returns a month, a plain text Order ID isn’t enough. Add a barcode so scanners can read it instantly. This cuts handling time and reduces errors.

When to Use a Packing Slip for Returns

If you accept returns, the packing slip becomes a critical document. Include the RMA number and the return address clearly. Some systems (like ReturnGO) let you customize the slip to show the Warehouse RMA ID and a barcode for 3PL processing. This feature is available on Pro or higher plans and works as an add-on for lower tiers.

One important detail: Do not use a packing slip for “no shipment required” return methods (e.g., return to store, drop-off without a box). The slip is only useful when a physical package moves.

Packing Slip vs. Invoice vs. Shipping Label

These three documents serve different purposes, but they often get mixed up.

• Packing slip: Stays inside the box. Lists items and quantities. No prices.
• Invoice: Sent separately or included in the box. Shows item prices, taxes, totals, and payment terms.
• Shipping label: Stuck on the outside of the box. Shows the delivery address, sender info, tracking number, and barcode. It’s for the carrier, not the recipient.

Keep them separate, and your fulfillment process will run cleanly.