Door Locks

Replacement Letter Boxes & Letter Plates for uPVC, Composite & Timber Doors

10 inch and 12 inch letter boxes with telescopic sleeves, draught brushes and matching internal flaps. “10 inch” and “12 inch” are only nominal sizes – measure your screw centres and the hole in the door before ordering.

Letter Box Measuring & Buying Guide

Shop Letter Boxes by Type

10 inch letter box10 inch letter boxesAround 265mm overall 12 inch letter box12 inch letter boxesAround 305mm overall Internal letter box coverLetter box coversInternal flaps & draught excluders Post box cam lockPost box accessoriesReplacement post box locks

How to Measure a Letter Box

  1. AScrew centres. Measure between the centres of the two fixing screws. This is the measurement that differs most between brands.
  2. BCHole in the door. Remove the old letter box and measure the width and height of the cut-out. The new sleeve has to fit through it.
  3. DDoor thickness. Check it falls inside the sleeve range shown on the product.
  4. Overall plate size. Make sure the new plate is large enough to cover any marks left by the old one.

Shop by Aperture Size

Measure the hole in your door (B × C above) and pick the matching width. A letter box fits when its sleeve is the same size as the hole or slightly smaller, and the plate still covers it.

223mm wide44mm high 254–260mm wide39–52mm high 262–264mm wide43–50mm high 269mm wide38mm high 275–280mm wide45–60mm high

Why nominal size isn’t enough: “10 inch” and “12 inch” are not standard sizes. Apertures in our range run from 223mm to 280mm wide, and screw centres differ between brands too. Each product page lists its exact aperture, screw centres and door thickness.

What to Look For

Draught & weather sealing

Brush seals and a sprung flap keep draughts and rain out. An internal cover adds a second barrier on exposed doors.

Telescopic sleeve

The sleeve lines the hole through the door and adjusts to the door thickness. Check the range suits your door.

Finish & matching furniture

Match the finish to your handles, knocker and numerals. Many ranges are available as a matching suite.

Letter Box Brands

  • Yale
  • Fab & Fix
  • Avocet
  • GreenteQ
  • Mila
  • Trojan
  • Ultion
  • Stormguard
  • Exitex

Frequently Asked Questions

Will a new letter box fit my uPVC or composite door?

Usually, as long as the screw centres, the hole in the door and the door thickness all fall within the new letter box’s dimensions. Those three measurements matter more than whether it is sold as 10 inch or 12 inch.

Are all 12 inch letter boxes the same size?

No. Overall length is around 305mm, but aperture sizes and screw centres can differ between brands by 20mm or more. Use the aperture size buttons above, then check the screw centres on the product page.

Can I reuse the existing hole in my door?

Yes, when the new sleeve fits through the existing cut-out and the fixing centres line up. If the centres are different you will need to drill new fixing holes, so check the new plate covers the old ones.

Can I stop draughts without replacing the whole letter box?

Often, yes. An internal letter box cover or draught excluder fits over the inside of the opening and can be added to most existing letter boxes.

Can I fit one of these to a fire door?

Only fit a letter plate that is specifically certified for use on fire doors. Check the individual product specification, and ask us if you are unsure.

Not sure which letter box will fit?

Send us a photo of your existing letter box with a tape measure across it and we’ll match it for you.

Use the part-identification form

Support hours Mon–Fri, 9am–3:30pm