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Phone GWP Packaging - 01793 754 444
01793 754 444
Mon - Fri / 08.00 - 17.00
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GWP Packaging

Corrugated cardboard packaging expertise & innovation

GWP Protective

Widest range of protective cases with custom foam in the UK


UK leading independent Correx® packaging manufacturer

GWP Conductive

Providing cutting edge ESD safe packaging for 30+ years

GWP Coatings

Supplying sheet plants with coated corrugated material

Reduce packaging costs

A range of strategies and ideas to reduce your ongoing packaging costs

Protective packaging

Protection for your products and equipment to prevent costly damage in transit

Improve packaging efficiency

Streamline your operations, enhancing efficiency & productivity

Environmentally friendly packaging

Minimise the environmental impact of your packaging and business

Packaging design service

Custom packaging to your exact requirements, designed by an award winning team

Packaging guides and blog

A range of guides, tips and detailed articles to improve your packaging

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Examples of successful packaging, and how your business can benefit

Packaging markets

Specific industry knowledge & expertise relevant to your business

Quality standards

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The latest news, events and community projects happening at GWP Group

Large Letter Boxes

Custom Design

Tailored to your requirements

UK Trade Supplier

Huge product selection

Reduce Costs

Range of strategies & services

Large letter boxes (PIP)

Cardboard Postal Boxes

Manufacture / trade supply of packaging to Royal Mail guidelines

This small postal packaging allows your business to reduce postage costs, by not exceeding Royal Mail PIP (Pricing in Proportion) guidelines for the large letter boxes category – 353 x 250 x 25 mm (L x W x D).

GWP Packaging manufacture your large letter boxes to your specific requirements – having taken this approach for nearly 30 years. This allows for bespoke sizes, carefully chosen material and tailored pricing, ensuring you benefit from the most cost effective option. Read More

Available Colours:

Brown Kraft Cardboard
Single Colour Print
Full Colour Print
  • No obligation (and no pressure) quotes for any packaging
  • Free and impartial advice from UK based experts
  • Competitive pricing and full customisation options


Detailed info on Large Letter Boxes

In 2013, the Royal Mail changed the way in which priced specific sizes of parcels and letters. Known as pricing in proportion, this meant to benefit from specific price bands, your business’ packaging had to fall within pre-defined dimensions / weights.

The large letter boxes as they have become known, must not exceed 353 x 250 x 25 mm (length x width x depth), and have a maximum weight (including packaging and contents) of 0.75 Kg.

As such, your business can source a range of corrugated packaging from GWP which satisfies these requirements.

However, you do not simply need to specify this maximum size. You can choose any size within this range to create a better, tailored fit for your specific products, enhancing the level of protection in transit. It can also help reduce costs by eliminating or minimising any void fill required too.

They can also be created in a range of styles, from pizza style boxes (also referred to as 0427) to 5 panel wraps which fold around your products. If you are unsure of the best design for your application, a member of the GWP team will be happy to advise.

Whatever style you select will be easy, quick and efficient to assemble, and supplied flat packed to minimise storage requirements.

Finally, besides choosing a bespoke size and / or style, you can also choose a natural, eco-friendly kraft brown finish, or a more premium white cardboard appearance. When coupled with a range of one, two or full colour print – that can be applied to the exterior or interior of your large letter boxes – it means you can perfectly match your brand identity.

Whatever options you decide are best for your business, any large letter boxes supplied will use a thin, lightweight yet durable single flute corrugated material. This allows the packaging to maximise the available space of the PIP box guidelines, but also keep the contents safe, secure and free from damage.

All of this makes the large letter cardboard boxes ideal for a range of applications. Any business or ecommerce site selling books, DVDs, computer software or similar sized items could potentially see lower shipping costs as a result of switching to this packaging.

Key features of these boxes at a glance

  • Meet the Royal Mail Large Letter guidelines (max 353 x 250 x 25 mm)
  • Can be produced to any size within these criteria
  • Manufactured from a thin yet durable single flute cardboard
  • Lightweight material also helps minimise costs
  • Can be produced in numerous, easy assemble styles
  • Supplied flat for easy storage
  • Protects your products throughout the delivery network
  • Available in either natural kraft or premium white finishes
  • Can be further customised with a range of interior / exterior print options


Large Letter Box technical details

Please use the tables below for the important sizes / weights etc. for these Royal Mail Large letter boxes.

Max External Sizes

353 mm
250 mm
25 mm

Weights / Charges

0.10 Kg
0.25 Kg
0.75 Kg (max)


Single Wall
Kraft / White

Tailored Pricing / Sizes

Cost effective packaging for your business

Unlike other suppliers of PIP boxes, GWP Packaging does not hold standard sized boxes. Everything we supply is manufactured bespoke to your business’ requirements.

Whilst this may sound strange for what are essentially boxes defined by a set size, by manufacturing bespoke it allows for packaging that not only provide optimum protection for your items, but is genuinely cost effective in mid to high volumes.

As a trade supplier, GWP is happy to provide you with no obligation quotes on a large letter boxes, guidance on the best packaging for your specific application, and to even advise if you would be better off purchasing stock boxes from a merchant or online seller (i.e. if you only require low volumes, or would not truly benefit from bespoke options).

Customisation / Options

Print, specialist coatings and more

If you need to enhance your large letter boxes to improve performance, appearance or security, then GWP can help.

You can choose from numerous print options, a range of specialist coatings (including adding water resistance) as well as tamper evident seals engineered directly into your company’s boxes.

Waterproof cardboard packaging

Water Resistant Coating

Protect your deliveries from rain and moisture

Tamper proof packaging

Tamper Evident Features

Prevent / highlight tampering in transit

Printed large letter boxes

1, 2 or Full Colour Printing

Add logos, graphics, instructions and more

Similar PIP Boxes

Similar options for your postal packaging

Small parcel boxes (PIP)

Small Parcel Boxes

PiP Box colours

450 x 350 x 160mm
Max Size (L x W x D)

Medium parcel boxes

Medium Parcel Box

PiP Box colours

610 x 460 x 460mm
Max Size (L x W x D)

Large parcel boxes

Large Parcel Boxes

PiP Box colours

> 610 x 460 x 460mm
External (L x W x D)

Postal book wraps

Book / Postal Wraps

PiP Box colours

Custom Sizes
Enquire for details

PIP boxes

View All PIP Boxes

Click here to see the full PIP boxes / packaging range

Postal packaging boxes and mailers

View All Postal Boxes

View all available postal packaging options

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Here to Help

Contact a member of our sales & support team directly

Gemma Loverseed

Gemma Loverseed

Product Adviser
[email protected]
01793 754 444

Jay Daggar, GWP Packaging Sales Manager

Jay Daggar

Sales Manager
[email protected]
01793 754 444

Ian Heskins

Ian Heskins

New Business Director
[email protected]
01793 754 444

Phone GWP Packaging

01793 754 444

Mon – Fri 08.00 – 17.00

Email GWP Packaging

[email protected]

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Large letter boxes not the perfect fit for your business? Then please view the other PIP box options...

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Contact Information:

GWP Packaging. Unit 20, Chelworth Park, Cricklade, Swindon, SN6 6HE, GB

TEL: 01793 754 444 | FAX: 01793 754 445
EMAIL: [email protected]

Business Hours: 08.00 a.m. to 17.00 p.m. Monday to Friday

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