How to Ship Smarter in 2026: 7 Packaging Mistakes to Avoid

Because good packaging should protect your profits, not eat them.

With postage prices on the rise, customer expectations sky-high, and sustainability under the microscope, 2026 is not the year to mess up your packaging. Whether you’re an e-commerce brand, subscription box business, or marketplace seller, how you ship your products can seriously impact your bottom line.

Here are the top 7 packaging mistakes businesses are still making - and how to fix them.

📏 1. Using Boxes That Are Too Big (or Too Small)

Oversized boxes increase your shipping costs, require more filler, and can damage your brand’s sustainability image. On the flip side, tight boxes can crush your products or cause bulging - a red flag for couriers and customers alike.

✅ Smart fix

• Use packaging that matches the item size as closely as possible.
• Stock a few core sizes - especially Royal Mail Large Letter and Small Parcel compliant boxes.
• Try crash-lock boxes for strength and efficiency.
• At Parcelsend UK, we offer a wide range of postal boxes to suit every size and format - all delivered fast and at competitive prices. View our range of postal boxes here.

🚚 2. Ignoring Royal Mail Sizing Rules

A few millimetres over the limit and your parcel goes from a Large Letter to a Small Parcel, or worse - triggering higher postage costs and sometimes delays or returns.

✅ Smart fix

• Know your thresholds: Large Letter = 353x250x25mm, up to 750g. Small Parcel = 450x350x160mm, up to 2kg.
• Use letterbox-friendly packaging whenever possible.
• Print postage in-house (e.g. with a franking machine) to avoid Post Office surprises.
• Our Large Letter sized packaging are a customer favourite - ideal for saving money and fitting through standard letterboxes. View our range of Large Letter sized packaging here.

🧻 3. Overfilling with Bubble Wrap or Void Fill

Yes, protecting your items is important - but overdoing the filler can sometimes be a hinderance. It makes parcels heavier, can look messy and unprofessional and also it can cost more to store and buy.

✅ Smart fix

• Choose snug-fitting boxes to reduce the need for filler.
• Use a all-in-one void fill protection box such as FlexHold™ Postal Boxes to keep costs down and protection. Find out more about Flexhold™ here.
• For fragile items, use just enough bubble wrap or switch to paper alternatives.

🎁 4. Not Considering the Unboxing Experience

Packaging isn’t just functional, it’s part of the customer experience. Sloppy, boring, or damaged packaging can reduce repeat business, even if the product inside is perfect.

✅ Smart fix

• Keep packaging clean, simple, and well-sealed.
• Add a personal touch - even with unbranded packaging (like stickers, tissue paper, or thank-you slips).
• For a more polished look, consider custom printed packaging from our sister site, Fast Printed Packaging. Unboxing is free marketing, especially in the era of TikTok and Instagram.

🧾 5. Using the Wrong Tape (or Not Enough of It)

Few things frustrate couriers (and customers) more than boxes popping open in transit due to cheap tape or poor sealing. It happens more often than you might think.

✅ Smart fix

• Use proper parcel tape - not masking, sellotape or flimsy stuff. View our range of high quality packaging tape here.
• Apply tape to all box seams, especially the base.
• Consider switching to paper tape — it’s eco-friendly, strong, and sticks like a dream.
• Use a tape dispenser to speed up your packing process.

📮 6. Relying on Only One Type of Mailer

There’s no such thing as a one-size-fits-all solution in packaging. Businesses often try to stretch one box or bag across all orders to save on cost - but this just leads to wasted space, higher costs, and more returns.

✅ Smart fix

• Stock a small range of boxes, bags, and envelopes.
• Include padded envelopes, poly mailers, and cardboard book wraps in your mix.
• Use Large Letter formats when possible to save money.
• Parcelsend offers bundles and bulk discounts so you can afford to stay flexible without breaking the bank.

💰 7. Forgetting That Packaging = Profit

Every return, damage complaint, or negative review costs you money - and it usually comes back to poor packaging.

✅ Smart fix

• See packaging as an investment, not an afterthought.
• Audit your current materials and look for cost-saving swaps.
• Use tools like franking machines, batch labels, and scaled packing stations to increase efficiency.

🏁 Final Thought: Pack Smart, Ship Smarter

In 2026, the smartest businesses are optimising their packaging just as much as their marketing, logistics, or operations. With a few smart tweaks - and the right supplies - you can cut costs, boost customer satisfaction, and keep your deliveries looking professional. View our range of packaging supplies here.

At Parcelsend UK, we supply affordable, quality-tested packaging essentials - so you can post faster, smarter, and greener. No fluff. No fancy designs. Just the stuff that works. Need help choosing the right packaging? Get in touch with our team today - we’re happy to help.