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MAXIMUM SLIM Large Letter Postal Boxes - Royal Mail PiP Boxes (333mm x 123mm x 20mm)

  • MAXIMUM SLIM Large Letter Postal Boxes - Royal Mail PiP Boxes (333mm x 123mm x 20mm)
  • Product Code: LL-MAXISLIMPIP#
  • £0.00

FREE SHIPPING on orders over £30 (ex VAT) to Most UK Mainland Addresses
Orders placed after 3.00 pm may not be shipped on the same day

Available Options


Maxi Slim Large Letter Postal Boxes - these large letter postal boxes are designed to provide the maximum length allowed under Royal Mail's Large Letter size restrictions but with half the width for narrower items.

Defenda Maxi Slim Large Letter Boxes

These top quality maximum length Large Letter PiP Postal Boxes (often called Slimline Large Letter Boxes, Narrow Large Letter Boxes or simply Slim PiP Boxes) are the longest length allowed as large letter boxes under Royal Mail Large Letter size restrictions. The narrower width of the box helps customers with narrower items reduce internal packing materials --- good for the environment and good for your wallet.

Large Letter Boxes

We hold a large range of various size Large Letter Boxes --- so if you are looking for the cheapest prices on other sizes of quality Large Letter Postal Boxes then check out our full range here. Alternatively we regularly manufacture custom made Large Letter Postal Boxes for clients. Therefore if you require custom postal boxes to fit into Royal Mail's Large Letter guidelines please contact us to discuss your exact needs.

Environmental Information

Our Maximum Size Large Letter Postal Boxes are manufactured by us here in the U.K. — so they don’t clock up huge amounts of import miles. They are produced using recycled & recyclable material.

Royal Mail Small Parcel Sized Boxes

We also manufacture and stock a large range of Small Parcel Boxes in various sizes that will conform to Royal Mail Small Parcel size restrictions. Follow the link to view our full range of Royal Mail Small Parcel Boxes.


Maximum Slim Large Letter Box Specification:

Narrow or Slim Large Letter Postal Boxes Internal Dimensions: 333mm x 123mm x 20mm
Board Grade: E Flute
Maxi Slim PiP Postal Box Individual Unit Weight: 37 grams (Appx)

Like all of our Large Letter Size Postal Boxes or PiP Boxes, these Maximum Size Slim PiP boxes are manufactured using quality board in an E flute --- maximising the strength of the box whilst leaving the sufficient space in the box for contents.

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Shipping Rates & Upgrades


FREE SHIPPING ON ORDERS OVER £30 (ex VAT)...
so no nasty surprises at checkout.

With the vast majority of items listed on this site being supplied without an additional charge for postage on orders over £30 NET .

The only time you may have additional charges is when you’re buying bulk quantities, very large items or you’re located offshore or in certain parts of the Scottish Highlands.

Please note that we cannot deliver to PO boxes.

Please check here for Offshore and Scottish Highlands shipping upgrades

If you require a faster delivery, click here for timed shipping upgrades

If you are ordering outside of the UK, please click here to see our international rates