Skip to content Discover our collection of custom mailer boxes made to fit your requirements. Need something else? Get in touch with us.
Protect your products with custom mailer boxes with inserts designed for secure shipping and a premium unboxing experience. At British Custom Boxes, we provide durable materials, precise inserts, and fully customized printing to keep items perfectly placed while strengthening your brand presentation.
Fill out our quote form today to get custom mailer boxes tailored to your needs.
A custom mailer box is a branded, self-locking corrugated cardboard box designed to be sent directly through a postal or courier network without requiring an outer carton. Unlike plain brown shipping boxes, custom mailer boxes carry your logo, brand colours, and artwork printed directly onto the board — inside, outside, or both.
The structure most commonly used in the UK is the FEFCO 0427 style. This is a roll-end tuck-top (RETT) design: the lid folds over the top and two side wings, called dust flaps, tuck in to hold the box securely closed. No tape or glue is needed during packing, which makes it fast to assemble at scale. The other popular style is the FEFCO 0426, a folder-style box where the base is hinged to form the side walls — ideal for flat items, garments, and documents.
Both styles ship flat-packed, so they take up minimal warehouse space until needed.
What makes a mailer box “custom”?
The word “custom” covers three distinct things that British Custom Boxes applies to every order:
The UK ecommerce market is one of the largest in Europe, and with it comes intense competition for customer attention. Research consistently shows that packaging is one of the few physical touchpoints a DTC brand controls completely. A plain brown box is a missed opportunity; a well-designed custom mailer box is a marketing channel that the customer paid for through their purchase.
Unboxing content on TikTok and YouTube has introduced millions of consumers to the idea that how a product arrives matters as much as the product itself. Brands that invest in packaging report higher rates of organic social sharing, repeat purchase, and positive review sentiment. The box is no longer just a container — it is part of the product experience.
A correctly sized custom mailer box protects its contents more effectively than an oversized plain box filled with void material. When dimensions are matched precisely to your product, the contents cannot shift during transit. This translates directly into fewer damaged goods, fewer returns, and lower replacement costs.
For UK businesses sending through Royal Mail, the dimensions of your mailer box affect how your parcel is classified and what you pay per shipment. Boxes designed to fall within Royal Mail’s Small Parcel band (up to 450mm × 350mm × 160mm, up to 2kg) cost significantly less to send than Large Parcel equivalents. British Custom Boxes can engineer your mailer box dimensions to stay within preferred size bands, which can save meaningful amounts across thousands of shipments per year.
A customer who receives a beautifully printed mailer box is more likely to remember the brand, return to buy again, and recommend the product to others. The box creates a sensory memory — the weight, the texture, the reveal — that a plain envelope or brown carton cannot replicate.
Choosing the right board is the single most important structural decision in your packaging project. It determines strength, print quality, weight, and sustainability credentials. British Custom Boxes supplies the following materials for custom mailer boxes in the UK.
E-flute is 1.6mm thick — the thinnest corrugated grade. It is strong enough for most ecommerce products up to approximately 2kg, folds cleanly without cracking, and accepts high-quality print extremely well. The smooth, tight flute structure means the surface is almost as printable as solid board. E-flute is the most widely used material for custom mailer boxes in the UK because it balances protection, weight, printability, and cost.
Typical applications: cosmetics, skincare, candles, books, jewellery, clothing accessories, gift sets.
B-flute is 3mm thick and significantly stronger than E-flute. It is used when products are heavier, when the box needs to resist stacking pressure in a warehouse, or when goods are fragile and the box itself needs to absorb impact. The wider flute means the surface is slightly less smooth than E-flute, but full-colour print is still achievable with the right process.
Typical applications: electronics, homeware, glass products, heavier subscription kit boxes.
Double-wall combines two layers of fluting (typically BC or EB) for maximum rigidity. It is used for high-value or very heavy products where any damage would be costly, and for export shipments where parcels face more handling steps. Print quality on double-wall is more limited — most clients use it with a litho-laminate approach (print onto paper that is then glued to the board surface).
Kraft is a natural brown fibre board. It has strong ecological associations and appeals to brands in organic, artisan, and sustainable product categories. Brown mailer boxes print well in single or two-colour, and kraft combined with a simple logo creates a clean, honest aesthetic. Full-colour printing on kraft is possible but colours will appear warmer and less bright than on white-coated board. British Custom Boxes uses FSC-certified kraft as standard.
White-coated board has a bright printing surface that brings out the full vibrancy of CMYK colour. If your brand relies on bold palette expression — vivid inks, photographic imagery, precise Pantone matching — white-coated E-flute or B-flute is the right choice. White mailer boxes are the most common substrate for premium ecommerce and subscription packaging in the UK.
British Custom Boxes manufactures eco mailer boxes from board with a minimum of 70% recycled fibre content, and we are FSC certified. All our corrugated board is recyclable and biodegradable. If your brand requires plastic-free packaging certified to FSC or PEFC standards, we can provide documentation to support your sustainability claims.
Print method affects both the visual result and the economics of your order. British Custom Boxes offers three primary print routes, and we’ll recommend the right one for your quantity and quality requirements.
Digital print uses inkjet technology to apply CMYK colour directly to the corrugated board without printing plates. There is no setup cost, which means the per-unit price of a small run (typically under 500 boxes) remains viable. Colour accuracy is excellent, turnaround is fast, and you can run multiple designs in a single order — ideal for seasonal variations, personalised mailers, or test runs before committing to a full production volume.
British Custom Boxes digital print orders typically ship within 5–7 working days from artwork approval.
Lithographic print is applied to paper, which is then laminated (glued) to the corrugated board. The result is the highest possible print quality for a packaging substrate — photographic level colour reproduction, sharp typography at small point sizes, and the ability to apply a wide range of surface finishes. Litho-lam is used by brands for whom the packaging is a genuine differentiator: premium gifting, luxury cosmetics, high-end subscription boxes, and retail-ready packaging.
Flexo print uses rubber or polymer plates to apply spot colours at high speed. It is the most cost-efficient route for large volumes (typically 2,000+ units) with simple one, two, or three-colour designs. Brand logos, text, and simple brand marks print cleanly with flexo. It is not suitable for photographic imagery or complex gradients.
After printing, the following finishes can be applied:
Sizing your mailer box correctly affects product protection, material cost, storage footprint, and postage classification. British Custom Boxes manufactures to any size you need. The dimensions below are common starting points — all can be modified.
| Size Label | Internal L × W × D | Typical Use |
|---|---|---|
| XS Mailer | 150 × 100 × 60mm | Jewellery, small cosmetics, accessories |
| Small Mailer | 200 × 150 × 80mm | Books, candles, skincare singles |
| Medium Mailer | 280 × 200 × 100mm | Subscription kits, clothing items |
| Large Mailer | 350 × 250 × 120mm | Multi-item subscription, homeware |
| XL Mailer | 450 × 350 × 160mm | Large clothing, footwear, gift sets |
Note: The XL dimensions above represent the upper boundary of Royal Mail’s Small Parcel rate. Orders requiring boxes larger than this will be classified as Large Parcels by Royal Mail.
Measure your product (or your filled product with its inner packaging) at its widest point in each dimension. Add 5–10mm to each side for easy insertion and to allow for tissue paper or void fill if required. Provide these internal dimensions when requesting a quote. If you have multiple products that ship in the same box, measure the assembled kit at its outermost points.
British Custom Boxes is designed to work with businesses at all stages of growth. We provide no MOQ .
Ecommerce brands in the UK face a specific packaging challenge: the box must survive a carrier network (often multiple handling steps), arrive at the customer’s door looking pristine, and create a positive brand impression — all while keeping per-unit costs under control. British Custom Boxes manufactures ecommerce mailer boxes with the board grades and closure structures proven to withstand UK courier handling without adding unnecessary weight.
Subscription boxes live or die by their unboxing experience. Subscribers share their monthly reveal on social media, compare notes in communities, and make renewal decisions partly based on how much they look forward to the box arriving. Printed mailer boxes for subscription services can use inside print to create a “moment of reveal” the second the lid opens — brand messaging, a seasonal welcome, a product guide, or a visual pattern that becomes associated with the subscription brand.
British Custom Boxes works with subscription brands from their first 100-box run through to monthly volumes in the tens of thousands.
The beauty industry is one of the highest-volume users of custom mailer boxes in the UK. Consumers in this category are highly sensitive to the tactile and visual quality of packaging. Soft-touch lamination, foil blocking, and inside printing create the premium feel that supports the perceived value of skincare and beauty products. We also manufacture custom mailer boxes with inserts specifically engineered to hold bottles, jars, and tubes securely during transit.
Garment brands increasingly use the mailer box as a brand asset — the unboxing has become part of the product story. Tissue paper, a branded sticker seal, and a printed inside lid create the boutique-shopping-bag moment that online clothing customers are looking for. We manufacture mailer boxes for apparel in sizes suited to folded T-shirts, accessories, and full outfit boxes.
Starting small shouldn’t mean plain packaging. British Custom Boxes offers low minimum orders specifically so that independent makers, Etsy sellers, small boutiques, and new DTC brands can access the same quality of custom printed mailer boxes as larger competitors. We support first-time packaging buyers through every step of the process.
Premium gifting calls for premium packaging. Our luxury mailer boxes combine premium white-coated board, litho print, soft-touch or gloss lamination, and foil or embossed logo detail to create a physical experience that communicates quality before the gift is even seen. These are used for corporate gifting, wedding favours, high-end product launches, and subscription gifting services.
British Custom Boxes manufactures eco-friendly mailer boxes using FSC-certified recycled board, water-based inks, and plastic-free finishes. If your brand’s sustainability credentials are a key part of your customer proposition, we can supply packaging that supports those claims — and provide the certification documentation you need for marketing purposes. Kraft board with simple one or two-colour print is our most sustainable option; white coated with water-based gloss varnish is a strong choice for brands that want colour print with minimal plastic coating.
A mailer box insert is a shaped inner tray, card divider, or foam liner placed inside the box to hold each product in a specific position. Inserts serve two purposes: protection and presentation.
For protection, an insert prevents products from moving inside the box during transit. A glass bottle that shifts even a few centimetres can contact the box wall under repeated impact from carrier handling. An insert eliminates that movement entirely, reducing damage rates for fragile or premium products.
For presentation, insert the structure of the unboxing experience. When a customer opens a box and finds each item positioned precisely — candle here, card there, sample sachet in its own pocket — the experience communicates care and attention that translates directly to perceived brand quality.
British Custom Boxes manufactures mailer box inserts in the following formats:
Custom mailer box pricing in the UK is determined by five variables: board grade, box dimensions, print method, finish, and quantity. Understanding how each variable affects cost helps you make the right decisions for your budget.
Board grade: E-flute is less expensive than B-flute. Double-wall is the most expensive per unit due to material volume.
Dimensions: A larger box uses more board. A box that is 20% larger in each dimension uses significantly more material than a standard size, so dimension accuracy matters economically.
Print method: Digital print has no setup cost but a higher per-unit cost at volume. Litho-lam has a setup cost but a lower per-unit cost above approximately 500 units. For high volumes, litho-lam becomes more economical despite the upfront investment.
Finish: Uncoated board is the lowest cost. Gloss lamination adds a moderate cost. Soft-touch, foil blocking, and embossing add progressively more per unit but represent a strong investment for premium products where packaging is a brand differentiator.
Quantity: Pricing scales significantly with quantity. A run of 100 boxes has a higher cost per unit than a run of 1,000 boxes, which has a higher cost per unit than a run of 5,000 boxes. We always give you per-unit pricing alongside total order cost so you can compare transparently.
Indicative Price Guide (digital print, E-flute, white, gloss lam, medium size):
| Quantity | Approximate Cost Per Box |
|---|---|
| 100 | £1.80 – £2.60 |
| 250 | £1.20 – £1.80 |
| 500 | £0.90 – £1.30 |
| 1,000 | £0.60 – £0.90 |
| 2,500+ | £0.40 – £0.65 |
Prices are indicative and vary with exact dimensions, print coverage, and finish. Request a specific quote for your requirements.
There are no die-cutting charges, no artwork fees, and no delivery charges on standard UK mainland orders.
For businesses ordering at volume — whether you run a fulfilment centre, manage multiple product lines, or have monthly shipping volumes above 2,000 units — wholesale pricing from British Custom Boxes provides consistent, structured cost reduction as your order size grows.
Wholesale clients benefit from:
Contact our wholesale team directly for a structured pricing conversation.
UK manufacturing. Every box we make is manufactured in the United Kingdom. This gives you shorter lead times, better production visibility, and a lower carbon footprint versus importing from overseas.
Free design support. Our in-house design team provides artwork support at no charge. Whether you need a full design from scratch or just a technical check on your existing files, we handle it.
Free UK delivery. There are no delivery charges on any standard mainland UK order, regardless of size.
No hidden fees. The quote we give you is the price you pay. No die charges, no plate costs, no artwork fees.
FSC-certified materials. We manufacture with FSC-certified board as standard, supporting responsible forestry and enabling our clients to make credible sustainability claims.
Dedicated account management. You’ll have a named contact at British Custom Boxes who knows your account, your products, and your deadlines.
| Feature | Details |
|---|---|
| Box Style | Custom Mailer Boxes (Roll End Front Tuck, Self-Locking Design) |
| Size | Fully Custom Sizes (length × width × height) |
| Material | Corrugated Cardboard (E-Flute, B-Flute) |
| Material Thickness | 16pt – 24pt (depending on flute type and box strength) |
| Printing Options | CMYK Full-Colour Printing, Pantone (PMS) Colour Matching |
| Printing Methods | Digital Printing, Offset Printing |
| Coatings | Gloss Lamination, Matte Lamination, Aqueous Coating |
| Finishing Options | Soft Touch Lamination, Spot UV, Foil Stamping, Embossing, Debossing |
| Add-ons | Custom Inserts, Dividers, Tear Strips, Extra Protection Layers |
| Durability | Strong & Protective for Shipping and E-commerce Use |
| Sampling | Digital Proof / 3D Mock-up; Physical Sample Available on Request |
| Turnaround Time | 8–10 Business Days (after artwork approval) |
| Shipping | 2–3 Business Days (UK delivery) |
| Minimum Order Quantity | No MOQ |
| Customization | 100% Custom Size, Print & Structure |
Custom mailer boxes are mainly used for shipping products safely while promoting your brand. UK businesses commonly use them for eCommerce orders, subscription boxes, clothing, cosmetics, and promotional packaging.
Yes, eco-friendly custom mailer boxes are available using recyclable and biodegradable materials. They are popular with UK brands looking to reduce plastic packaging and meet sustainability goals.
Yes, we offer custom mailer boxes with no minimum order quantity (No MOQ). This is perfect for UK startups, small businesses, and brands that want flexible ordering without bulk commitments.
We use durable corrugated cardboard and kraft materials that provide strength, protection, and a professional finish. These materials are commonly preferred by UK brands for reliable shipping packaging.
Yes, custom mailer boxes are a cost-effective packaging solution for UK small businesses. They combine product protection, branding, and marketing in one box, reducing the need for extra packaging materials.
Our standard turnaround time is 8–10 working days after artwork approval. This allows UK businesses to receive high-quality printed mailer boxes without long waiting periods.
Yes, you can fully customise your mailer boxes with your logo, brand colours, text, and artwork. Printed mailer boxes help UK businesses create a strong brand impression when customers receive their orders.
From your requirements to delivery, we make getting custom packaging quick, easy, and reliable.
Tell us your box size, style, quantity, and print preferences. Our experts help you choose the perfect option.
We ship your boxes safely and on time, straight to your door, ready to go on the shelves.
Your boxes are printed with care, inspected for quality, and packed to impress your customers from the first unboxing.
Once production is complete, we will double-check everything and pack your custom-made mailer boxes securely for delivery.
