How to Fold a Mailer Box: A Step-by-Step Guide

Mailer boxes are one of the most popular packaging solutions for e-commerce businesses. They are lightweight, sturdy, and easy to store flat before use.

But for many first-time users, folding them correctly can be a bit tricky. Don't worry — we've got you covered.

In this guide, we'll walk you through how to fold a standard mailer box step by step.

What You'll Need

A flat mailer box (corrugated cardboard)
A clean, flat surface
Optional: packing tape (if sealing is required)

Step 1: Lay the Box Flat

Place the unfolded mailer box on a flat surface with the printed side facing down. Make sure all creases are visible and the box is fully opened.

Step 2: Fold in the Side Panels

Push the two shorter side panels inward along the pre-scored crease lines. These will form the sides of your box.

Step 3: Fold the Bottom Flaps

Fold the bottom flaps inward one by one. Start with the larger flap, then tuck in the smaller ones. Make sure they overlap neatly to create a solid base.

Step 4: Secure the Bottom (Optional)

If your mailer box does not have a self-locking bottom, use packing tape to seal the bottom flaps firmly. This ensures your items stay safe during shipping.

Step 5: Place Your Items Inside

Now your box is ready! Gently place your products inside. For extra protection, consider adding bubble wrap or kraft paper padding.

Step 6: Close and Seal the Top

Fold the top flaps in the same order as the bottom. If your mailer box comes with a peel-and-seal strip, simply remove the liner and press firmly to close. Otherwise, use packing tape to seal the top.

Pro Tips

Tip	Description
Pre-crease	Run your fingers along all fold lines before assembling to get cleaner edges.
Use the right size	Choose a mailer box that fits your product snugly to reduce movement during transit.
Test one first	Before mass packing, try folding one box to make sure you're comfortable with the process.

Why Choose Wondrous Packaging?

At Wondrous Packaging, we design mailer boxes that are:

Easy to fold with clear crease lines
Made from high-quality corrugated board
Customizable with your brand logo and colors
Eco-friendly and recyclable

Our mission: 'No Guesswork, Safe Sourcing, Good Sleeping.' We take the hassle out of packaging so you can focus on growing your business.

Need Help?

If you have any questions about folding or customizing your mailer boxes, feel free to reach out to us. We're always happy to help!

How to Fold a Mailer Box