Ensuring the parcels you send fit as closely to the available postal sizes as possible can really help to reduce your postal costs. Our great value range of postal boxes are designed specifically for cost-effective posting and we’ve got 5 styles and over 40 sizes to choose from, so we’ve put together this guide to help you choose the right postal box for you.
At A Glance
| Grade | Postal Size | Tape Free? | Choose When | Eco Score |
| Standard | Large Letter & Small Parcel | ❌ | You need a cost-effective, lightweight postal packaging solution for a range of items. |  |
| Modular Postal Boxes | Small Parcel | ✅ | You need a reliable, strong, space saving solution that keeps postal costs low. |  |
| Extra Secure Postal Boxes | Small Parcel & Medium Parcel | ✅ | You want to securely send valuable, fragile items or electronics. | |
Postage Guide
📮 Royal Mail Size Guide
Large letter, small parcel, medium parcel — size thresholds, weight limits & how to avoid overpaying on postage.
Standard Postal Boxes
Our pizza style Postal Boxes are a secure, cost effective way to send a wide range of items. Ideal for despatch operations running on a small budget, these low-cost mailing boxes are fast to assemble, have an integrated locking tab and are completed with packing tape for extra security. Supplied flat pack to save on storage space, all sizes of these postal boxes can be sent either Royal Mail Large Letter or Royal Mail Small Parcel to ensure you keep postal costs to an absolute minimum.
Our Standard Postal Box range also included our range of PIP Postal Boxes. The thinnest and most compact of all our ranges, these boxes allow you to send your small, lightweight boxes which comply with Large Letter sizing. Sturdy, protective and easy to assemble, we’ve got 5 sizes to choose from – look out for the PIP product code.
ColomPac Modular Postal Boxes
These ColomPac® Module Boxes are designed to stack perfectly in all combinations to reduce despatch cubic volume and optimised to fit within the major postal sizes to reduce your postal costs. As with all ColomPac® products strong peel and seal closure, papercut free edges and an easy open tear strip come as standard making these boxes fast, safe and user friendly. To find out more and see them in use take a look at our CP080 Module Box demonstration video.
ColomPac Extra Secure Postal Boxes
If you’re sending valuable or fragile items, ColomPac® Extra Secure Postal Boxes provide the ultimate protection. These boxes are extra robust and secure with double folded extended edges for outstanding corner and side impact protection and double layered corrugated cardboard all round.
The CP 066.02 and CP 066.04 are also compatible with the stretch film tray inserts for securing smartphones and tablets making them the best choice in our range for securely sending electronics. We’ve got 6 sizes available in this range and you can see them in action in our demonstration video here.
Priory Elements EcoBoxes™
Our Priory Elements EcoBoxes™ are the perfect planet-friendly postal box solution for mailing a wide range of smaller goods. Super quick and easy to assemble thanks to the peel and seal closure, great for an efficient pack and despatch process - plus, there’s no need for additional tape, reducing your packaging waste. Featuring a tear open strip, customers can easily open their EcoBoxes fuss-free. Made from sustainably sourced materials, fully recyclable, biodegradable, and plastic free - these Priory Elements postal boxes are a great addition to any eco conscious businesses looking to go a little greener.
ColomPac Instant Bottom Boxes
Ready-to-Use: ColomPac Instant Bottom boxes are designed for immediate use. Their crash-lock design allows the box to pop into shape effortlessly, ready for packing in a single movement.
No Tape Required: Forget about packing tape or additional sealing materials. These boxes feature a specially positioned strip of ColomPac self-seal tape on the lid section, ensuring secure closure without the hassle of extra adhesives.
Space-Saving: The quick pop-up assembly saves time and storage space. Whether you’re running a small budget operation or need efficient despatch solutions, these low-cost mailing boxes fit the bill.
Versatile Sizes: Available in various dimensions, ColomPac Instant Bottom Boxes can be sent either as Royal Mail Large Letters or Royal Mail Small Parcels, helping you keep postal costs to a minimum
Shop Colompac Instant Bottom Boxes
ColomPac Variable Depth Boxes
ColomPac Variable Depth Boxes offer a smart and adaptable solution for your packaging requirements. These boxes are designed to accommodate varying product sizes and quantities, making them ideal for businesses that deal with a diverse range of items. The standout feature of these boxes is their adjustable depth. Unlike standard fixed-size boxes, ColomPac Variable Depth Boxes allow you to customize the height based on the specific contents you’re shipping. Whether you’re sending a single product or a combination of items, these boxes adapt effortlessly. This flexibility is particularly valuable for businesses with changing inventory or irregularly shaped goods.
With instant pop-up assembly, these boxes save you time during despatch. The pre-folded creases allow you to precisely fit the box to suit your specific requirements. No need for additional tape or sealing materials—simply fold the box into shape, secure the self-seal strip, and you’re ready to pack.
ColomPac Variable Depth Boxes are made from high-quality, robust corrugated cardboard. They provide reliable protection for your items during transit. Available in a range of popular sizes, these boxes cater to various shipping needs. Whether you’re sending books, electronics, or delicate products, there’s a variable depth box to suit your requirements.
By eliminating the need for multiple box sizes, you save both money and storage space. These boxes adapt to the packed depth of your goods, streamlining your packaging process. The peel-and-seal adhesive closures ensure secure sealing without the hassle of additional tape.
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ColomPac Euroboxes
ColomPac Euroboxes are a game-changer when it comes to sustainable packaging solutions. These boxes are designed with both functionality and eco-friendliness in mind, making them a top choice for businesses looking to reduce their environmental footprint without sacrificing quality. What sets ColomPac Euroboxes apart is their sturdy construction, which ensures that your products are well-protected during transit while also being made from recycled and recyclable materials. This means that not only are you keeping your goods safe, but you're also contributing to a circular economy by choosing packaging that can be reused or recycled after use.
Another key feature of ColomPac Euroboxes is their versatility. Available in various sizes and configurations, these boxes can accommodate a wide range of products, from small items to larger goods. This versatility makes them ideal for businesses of all sizes and industries, whether you're shipping delicate electronics or bulky merchandise. Plus, ColomPac Euroboxes are designed for easy assembly, saving you time and hassle in the packaging process. Overall, with their combination of durability, eco-friendliness, and versatility, ColomPac Euroboxes are a smart choice for businesses looking to package their products sustainably without compromising on quality or convenience.
We hope the above advice gives you all the help you need to choose the right style of postal box for your needs. eCommerce despatch operations are our speciality so if you have any unanswered questions or require further assistance then please get in touch – we’ll be more than happy to help.