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Hello everyone, please note orders must be received by 11.45am each working day to qualify for next working day delivery.

Packaging Guide: Large Letter

Large letter postal boxes can be highly beneficial for ecommerce businesses as they are cost effective, convenient for your customers and significantly reduces the risk of ‘failed to deliver’ returns.

These boxes are perfect for shipping a wide range of items, from subscription boxes to items such as t-shirts/clothing, DVD’s, magazines and small electrical items.

Large Letter Package Sizing

Our large letter postal boxes come in two sizes. These are both compatible with Royal Mail’s large letter guidelines and most UK letterboxes.

C5 Large Letter PIP Postal Box

9.02 x 6.26 x 0.63" (229 x 162 x 20mm) From 14p per box

C4 Large Letter PIP Postal Box

12.83 x 8.94 x 0.63" (324 x 229 x 20mm) From 21p per box

The dimensions given refer to the internal dimensions of the box and you can send packages that weigh up to 750g.

How to Pack and Secure Your Package

Our large letter postal boxes are made out of top quality board that are delivered flat packed to reduce storage space before use. They can be easily assembled and are designed to be sturdy, ideal for going through the letterbox.

To Assemble and Pack:

  • Start by laying the box in front of you
  • For each indentation, fold the cardboard inwards, then you’re ready to pack
  • Place product flat in the box
  • If the product does not fill the whole box we recommend filling the excess area with eco friendly padding to protect your product
  • Once you have closed the box, secure by taping around the edges of the lid

Simple as that!

Key Benefits

  • Cost effective
  • Reduces excess packaging
  • Convenience for your customer
  • Plastic free and 100% recyclable
  • Made in Britain

Cost to Send Large Letter Postal Boxes

  • 100g =£1.06
  • 250g = £1.50
  • 750g = £2.72

Our boxes come in packs of 50 and you can order as many as you like. Plus, there is a bulk buy discount when purchasing 600 or more boxes.

We also offer free standard next working day delivery on orders paid for before 11:45 (excluding bulk orders).

Thousands of boxes supplied to clients throughout the UK


The one of the best box supplier in the UK I have ordered boxes from Boxed Up many times. They have great prices, very quick response time, next day delivery. What else can I say: The one of the best box supplier in the UK, Thank you

PNP Fragrance
PNP Fragrance

Regularly order from this company as the products and the service is excellent.

Katie Barker
Katie Barker

Good Sturdy Boxes We have been using Boxed Up for a few years now, and is an integral part of us meeting our customers' expectations. They offer a friendly and professional service. The only negative we have is that their new website has been 'coming s