How to Fit a Letter Plate into a Timber Door: A DIY Guide

Fitting a new letter plate is a manageable DIY job if you have the right tools, take accurate measurements and work carefully. In this guide, we explain how to fit a letter plate into a timber door, from marking the opening to checking the finished installation.

These instructions provide general guidance only. Before starting, check the dimensions of your chosen letter plate and make sure it is suitable for your door.

Tools you will need

  • Tape measure

  • Pencil

  • Spirit level or square

  • Drill and suitable drill bits

  • Jigsaw or another suitable cutting tool

  • Screwdriver

  • Masking tape

  • Safety glasses

  • File or sandpaper

Before you start

Check the letter plate and all supplied fixings before beginning the installation. Measure the overall width and height of the letter plate, paying particular attention to the size of the opening required through the door.

Make sure the proposed position will not interfere with the lock, internal strengthening, glazing, panels or any other door furniture.

Important: Always use the dimensions of the actual product as your guide. Never cut the door using nominal or catalogue dimensions alone.

1. Mark the position

Decide where you would like the letter plate to sit. Measure carefully and mark the centre point of the required opening on the face of the door.

Using a spirit level or square, draw the outline of the opening required for the letter plate. Check that it is level and confirm every measurement before making a cut.

Measure twice, cut once.

2. Protect the door surface

Apply masking tape around the area you will drill and cut. This helps to protect the door's finish and may reduce splintering, especially on painted, veneered or otherwise finished timber doors.

If needed, transfer your cutting marks onto the masking tape so they remain clear and easy to follow.

3. Drill the corner holes

Put on your safety glasses, then drill a hole inside each corner of the marked opening. Each hole must be large enough to accept the jigsaw blade.

Keep the drill square to the face of the door as you work.

4. Cut the opening

Insert the jigsaw blade into one of the drilled holes and carefully cut along the marked lines. Work slowly and allow the tool to do the work rather than forcing the blade.

Once the section has been removed, smooth and clean the edges of the opening with a file or sandpaper.

5. Test-fit the letter plate

Place the letter plate into the opening and check that it sits square and flush against the door. The opening should provide enough clearance for the letter plate without leaving excessive space around it.

If necessary, remove the letter plate and make small, careful adjustments to the opening.

Do not force the letter plate into position.

6. Mark and drill the fixing holes

Hold the letter plate in its correct position and mark the location of each fixing hole. Remove the letter plate, then drill the fixing holes with a drill bit suited to the supplied fixings.

If the product uses bolt-through fixings, make sure the holes pass straight through the door and remain correctly aligned on both sides.

7. Fit the letter plate

Position the external and internal components on the appropriate sides of the door. Insert the supplied screws or fixing bolts and tighten them carefully.

Tighten each fixing gradually and evenly, checking that the letter plate stays level and sits flat against the door.

Do not overtighten the fixings. This could damage the letter plate, the door surface or its finish.

8. Check the finished installation

Once the letter plate is installed:

  • Check that it is level, secure and sitting evenly against the door.

  • Open and close the flap several times.

  • Make sure the flap moves freely and returns to its correct position.

  • Check that the fixings do not obstruct its operation.

  • Remove the remaining masking tape and clean the surrounding area.

Caring for your letter plate

Clean the letter plate with a soft, dry or slightly damp cloth. Do not use abrasive cleaners, metal polishes or harsh chemical products unless they are specifically recommended for the finish.

Some decorative finishes naturally change in appearance over time. This is particularly true of unlacquered brass and other living finishes, where the developing patina is part of the product's character.

A final note before installation

These instructions are intended as general fitting guidance. Door construction and letter plate designs can vary, so always follow any product-specific instructions supplied with your chosen model.

For fire-rated, security-rated, composite, aluminium or uPVC doors, check the door manufacturer's requirements before drilling or cutting. Altering the door could affect its fire, security or weather performance and may invalidate its warranty.

If you are unsure about any stage of the installation, we recommend asking a suitably qualified installer to complete the work.

SDS London offers a wide selection of letter plates in different styles, sizes and finishes to complement both traditional and contemporary doors. Explore the collection online or speak to our knowledgeable team for help choosing the right design for your project.