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LB23 - 12 inch Narrow Letterbox

Price From: £17.79 Exc Vat £21.35 Inc Vat

In stock

Aluminium 12 inch Narrow Letterbox

  • Suitable for upvc or aluminium doors with narrow frames.
  • All metal surround and letterplate made from aluminium.
  • Foam seal/pad fixed to flap to stop draughts and leaks.
  • Strong springs means non-rattle.
  • Actual sizes are 317mm x 50mm.
  • Help video: How to fit a upvc letterbox
  • Help Guide: How To replace a letterbox for uPVC Door
  • FAQs: Customer questions about replacement upvc letterboxes
  • Detachable telescopic sleeves (40-80mm door thickness) mean you can just attach the front and back plates or clip the sleeves into place for a fully enclosed postal slot.
  • Self tapper screws provided for upvc for an easy fix (screw straight into your door).
  • Not suitable for coastal designated areas. Please contact for more details.
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12 inch Narrow Letterbox General Information


Hole through the actual sleeve of the unit is 260mm x 30mm with 292mm fixing centres. Postal slot on your existing letterbox can be between 280mm x 40mm max.


A robust UK manufactured slimline 12 inch narrow letterbox for use with PVC and aluminium double glazed doors. An all metal construction surround and plate give this letterbox a real quality feel! The flaps are designed to open to 95 degrees and this narrow letterbox will even take A4 post comfortably!

A lot of the old aluminium double glazed doors used this narrow slimline letterbox as standard so this model provides an ideal replacement. Due to the narrowness of the letterbox the postal slight is somewhat challenged to provide sufficient space for an adequate level of post which is why the brush seal is left out of this design. The weather sealing performance is however not compromised as the outer letterplate flap contains a thick foam pad which provides a seal against window and rain ingess when closed.


One of the big features of this 12 inch narrow letterbox is the detachable sleeve. The letterbox unit comprises of two halves of the inner sleeve which slide within one another when the letterbox is together but they can be detached if not needed, or even if you want to cut down the length of the sleeve as this will be easier to do. This leaves you free to consider using just the letterplates each side.

Video: Watch a short product demonstration of this product and its unique detachable sleeved letter plate.



To fix this letterplate to the door requires only the use of a self-tapping screw for upvc (supplied) or if a double glazed aluminium door then rivets can be used. The screw holes are positioned centrally at 292mm centres.



It's easy to look after this letterbox by cleaning with a dry cloth. It needs nothing more than that so please avoid any chemical cleaners as they are needed and can degrade the finish. 

Not suitable for coastal designated areas. Please contact for more details.

European Deliveries: Suspended from 21st Dec 2020 until further notice..

Coronavirus: Orders are currently being dispatched on time but couriers may take longer to get to you due to issues surrounding Coronavirus. Delivery times quoted cannot be guaranteed.

Hermes Delivery is currently taking between 1 and 5 working days.

If you have received your tracking number via email from Hermes you can check the status here.

If you want to find a Hermes parcel shop use this link here.

* UK deliveries over 15kg in weight will be delivered by DPD.

** Does not include weekend or Bank Holiday delivery days.

Delivery Charges Hermes and DPDHermes TrackingHermes Parcelshops


The following special offers are available to you when you buy the 12 inch Narrow Letterbox. The discount for the special offer will show in the cart if both the 12 inch Narrow Letterbox and the special offer product are added.

Customer Reviews 1 item(s)

  • Price
    Review by Alice Lynch
    (Posted on 07/04/2015)
    "Helpful and knowledgeable!"
    Letterbox is a perfect fit - lady on the phone helpful and knowledgeable about product. Delivery fast and easy to track. Very happy customer - just wish all online stores were this efficient!

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