How to Choose a Chrome Letterbox: Sizes, Letter Plates, Tidies and Draught Excluders Explained

A chrome letterbox is one of the most visible pieces of front door furniture. It needs to look right from the outside, sit neatly on the inside, accept post easily and help reduce draughts where possible. The finish matters, but the size and fitting details matter even more.

If you are replacing an existing letterbox, do not choose by appearance alone. The new letter plate must suit the door cut-out, fixing centres, aperture size and door thickness. If these measurements are wrong, the new chrome letterbox may not line up with the existing holes, may leave marks visible, or may not operate smoothly.

This guide explains how to choose the right chrome letterbox or letter plate for your door, how to measure correctly, when to use an internal tidy, and when a draught excluder or telescopic letterbox is the better choice. For a coordinated entrance, you can also match your letterbox with other polished chrome door furniture such as door numbers, knockers, centre knobs, bell pushes and cylinder pulls.

Polished chrome horizontal letterbox fitted to a blue front door — A polished chrome letterbox gives a clean, bright finish and works especially well with blue, black, grey, white and painted timber doors.

Start here: the 5 decisions that matter most

A letterbox looks like a simple product, but there are several details that affect whether it will fit properly. Before choosing the style, answer these five questions.

Are you replacing an existing letterbox or fitting a new one? Replacement projects are more measurement-led because you need to cover the existing cut-out and fixing holes.
Is your door timber, uPVC or composite? Timber doors often use traditional letter plates, while uPVC and composite doors often need telescopic letter plates or shield-style systems.
Do you need an outside plate only, an internal tidy, or a full letterbox set? The outside face and inside face of the door may need different pieces.
Is draught reduction important? If the hallway feels cold, look at internal tidies with draught excluders, brush strips, seals or telescopic options.
Do you want the letterbox to match other front door furniture? The best finish usually comes from matching the letterbox with chrome numbers, a chrome knocker, a centre knob or other polished chrome fittings.

Letterbox, letter plate, letter tidy or draught excluder: what do you actually need?

The words are often used interchangeably, but they do not always mean the same thing. Understanding the difference makes it easier to buy the correct part.

Letterbox or letter plate

This is the external flap or plate fitted to the outside of the door. It covers the slot where post is pushed through. In many product names, “letterbox” and “letter plate” describe the same outside fitting.

Internal letter tidy

A letter tidy is fitted to the inside face of the door. It covers the internal cut-out, gives the inside of the door a cleaner finish and can help hide rough edges around the opening.

Draught excluder

A draught excluder helps reduce air movement through the letterbox opening. It may be built into an internal tidy or included as part of a telescopic letterplate design.

Telescopic letterplate

A telescopic letterplate has an internal sleeve or tunnel through the door. It is commonly used on uPVC and composite doors, helping guide post through the door rather than letting it drop into the internal door cavity.

Measure before choosing a chrome letterbox

The safest way to choose a replacement chrome letterbox is to measure the existing fitting before removing it completely. Take measurements in millimetres and write them down before browsing.

Diagram showing how to measure a letterbox aperture, fixing centres and door thickness — The key measurements are the overall plate size, aperture size, fixing centres and door thickness.

Measurement	What it means	Why it matters
Overall plate size	The full width and height of the visible outside plate.	The new plate needs to cover the existing cut-out, old marks and any exposed paint lines.
Aperture size	The size of the opening where post passes through.	The aperture needs to be large enough for everyday post, but the door cut-out must also allow the flap to move freely.
Fixing centres	The distance between the centre of one fixing bolt or screw and the centre of the other.	This determines whether the new letterbox lines up with existing fixing holes.
Door cut-out	The slot cut through the door itself.	The outside plate and internal tidy need to cover the cut-out neatly on both sides.
Door thickness	The depth from the outside face of the door to the inside face.	Important for telescopic letterplates, shield systems and any product that passes through the door.

If you are replacing an old chrome letter box, measure the existing outside plate first. Then open the flap and check the aperture, fixing bolts and inside face of the door. If there is already an internal tidy, measure that too. The inside tidy may need to be larger than the outside aperture so it fully covers the internal opening.

Choosing a replacement letterbox: three common situations

The best product depends on what is already fitted to the door. Use the situation below that most closely matches your project.

1. You want a simple like-for-like replacement

Choose a chrome letterbox with similar overall dimensions, similar fixing centres and an aperture that suits the existing door cut-out. This is usually the easiest route because it reduces the need for drilling, filling or repainting.

A like-for-like replacement is best when the existing position works well, the door is in good condition, and you simply want a fresher polished chrome finish.

2. You want to cover old marks or a rough cut-out

Choose a slightly larger outside plate and a suitable internal tidy. This can help cover paint marks, previous screw holes, a rough opening or damage around the old letterbox.

Be careful not to choose only by overall size. The new fixing centres and aperture still need to work with the existing door.

3. You want better draught reduction or privacy

Look for an internal tidy with a draught excluder, a letterplate with brush or gasket features, or a telescopic option if the door type suits it. These products are especially useful on exposed front doors, cold hallways and doors facing busy streets.

Choosing the outside style: plain, decorative, postal knocker or vertical

Once the measurements are clear, you can choose the external style. The outside letterbox is part of the door’s kerb appeal, so it should suit the door design as well as the rest of the hardware.

Plain horizontal chrome letterbox

A plain horizontal letterbox is the most versatile choice. It suits modern, traditional and painted timber doors. Choose this when you want the finish to look smart without adding decorative detail.

Decorative letterbox with raised letters

A raised-letter design gives the door a more traditional look. It can work well on period-style doors or homes where the front door furniture is meant to be more noticeable.

Postal knocker letterbox

A postal knocker letterbox combines a letter plate with a small knocker feature. It is useful when space is limited or when you want one piece of hardware to perform two visual roles.

Vertical letter plate

A vertical letter plate may suit narrow door stiles, specific door designs or existing vertical cut-outs. Replacement accuracy is especially important because the opening and fixing points are less forgiving.

Polished chrome postal knocker letterbox fitted to a black front door — A postal knocker letterbox is a good option when you want a traditional look without fitting a separate large door knocker.

Do you need an internal letter tidy?

The outside of the door is only half the job. The inside face matters too, especially if the cut-out is visible from a hallway. An internal letter tidy covers the inside opening and gives the door a more finished appearance.

An internal tidy is particularly useful when:

the inside cut-out looks rough or unfinished;
you are replacing an older letterbox and want to hide previous marks;
the hallway side of the door is highly visible;
you want the internal side to match the external chrome finish;
you want to add a flap or cover to reduce visibility through the opening.

Polished chrome inner tidy for the inside face of a letterbox opening — An inner tidy is fitted to the inside face of the door to cover the internal letterbox cut-out.

When choosing a tidy, check that it covers the internal opening and suits the width of the letter plate on the outside. It should look balanced on the door and have enough coverage around the cut-out to hide any rough edges.

When to choose a draught excluder

A letterbox creates an opening through the door, so it can be a common source of draughts. If your hallway feels cold, if the door faces strong wind, or if you can feel air movement around the letter plate, a draught-reducing option is worth considering.

A draught excluder may use a brush strip, foam seal, flap or gasket to help reduce airflow. It will not turn a poor-fitting door into a fully insulated one, but it can make the letterbox area more comfortable and better finished.

Polished chrome internal letterbox tidy with draught excluder fitted to a front door — An internal tidy with a draught excluder is useful when you want a neater inside finish and better protection from cold air.

Choose a draught excluder if:

the front door opens into a hallway or living space;
you can feel cold air around the current letterbox;
the property is exposed to wind or weather;
you want to reduce visibility through the letterbox opening;
you are already replacing the internal tidy.

Chrome letterboxes for uPVC and composite doors

uPVC and composite doors often need a different style of letterbox from a traditional timber door. Many use telescopic letterplates, where the internal sleeve passes through the depth of the door. This helps guide post through the door and prevents it dropping into the space between the door panels.

For uPVC and composite doors, check:

overall plate size;
fixing screw centres;
internal sleeve size;
door thickness range;
whether the product is face fixed, through fixed or offers both options;
whether an external and internal section need to be purchased together.

Hardex chrome telescopic uPVC letterplate fitted to a red front door — Telescopic chrome letterplates are commonly used on uPVC and composite doors because they pass through the door depth.

If your door currently has a telescopic letterbox, replace it with another telescopic option unless you are changing the door setup. A traditional surface-mounted letter plate may not be suitable for the same opening.

Security and privacy considerations

Letterboxes are designed for access, but that access should still be controlled. On external doors, especially doors with internal thumb turns, glazing or nearby keys, it is worth thinking about privacy and security as well as appearance.

Consider whether the letterbox:

limits visibility into the hallway;
has an internal flap or shield;
helps prevent fishing through the opening;
suits the security requirements of the door;
is appropriate for timber, uPVC or composite construction;
works with the rest of the door package.

For some uPVC, composite and security-focused doors, shield-style letter plates or certified systems may be more suitable than a simple decorative letter plate. Always check the individual product details if security performance is a deciding factor.

Matching a chrome letterbox with the rest of the front door

A chrome letterbox rarely sits alone. It is usually close to house numbers, a door knocker, bell push, centre knob, cylinder pull, escutcheon or pull handle. Matching these pieces gives the entrance a more deliberate and complete look.

For a coordinated front door, match your chrome letterbox with:

chrome door numbers or letters;
a polished chrome door knocker;
a chrome centre door knob;
a chrome bell push;
a chrome cylinder pull or escutcheon;
chrome hinges or hinge covers where visible.

Polished chrome works especially well on dark painted doors because the bright finish stands out clearly. On white or pale doors, it gives a cleaner and more subtle effect. If you already have satin chrome, stainless steel or nickel hardware nearby, compare the finishes carefully before mixing them on the same door.

Useful chrome letterbox examples

These examples show how different chrome letterbox styles solve different buying needs.

Polished Chrome Horizontal Letter Box 306x104mm — a larger horizontal letterbox for a clean front door finish.
Polished Chrome Victorian Plain Letter Box 10x3in — a traditional plain style with a sprung flap.
Polished Chrome Letter Box with Raised LETTERS — a more decorative option for period-style doors.
Heritage V830 Polished Chrome Postal Knocker Letter Box — combines a letter plate and postal knocker detail.
Polished Chrome Inner Tidy 406x120mm — useful for finishing the inside face of the door.
Polished Chrome Internal Tidy with Draught Excluder — useful when internal appearance and draught reduction are both important.
Fab and Fix Nu Mail Telescopic uPVC Letterplate in Hardex Chrome — a telescopic option for suitable uPVC and composite doors.

Common mistakes when buying a chrome letterbox

Only measuring the outside plate

The overall plate size is important, but it is not enough. You also need the aperture, fixing centres, door cut-out and door thickness where relevant.

Ignoring the inside of the door

The outside may look perfect while the inside remains rough or unfinished. If the hallway side is visible, consider an internal tidy at the same time.

Choosing a plate that is too small

A smaller letterbox may expose old screw holes, paint lines or a larger cut-out. Replacement letterboxes often need to be the same size or slightly larger.

Confusing aperture size with door cut-out size

The aperture is the opening in the letter plate, but the door cut-out may need to be larger to allow the flap and hinge mechanism to move properly.

Buying a timber-door letter plate for a uPVC door

Many uPVC and composite doors need telescopic or specialist letterplates. Check the door material and thickness before ordering.

Forgetting draughts and privacy

If the hallway is cold or visible through the current opening, a plain outside plate may not be enough. Look at internal tidies, draught excluders or shield-style products.

Chrome letterbox buying checklist

Measure the existing outside plate width and height.
Measure the aperture where post passes through.
Measure fixing centres from the centre of one fixing hole to the centre of the other.
Check the size and condition of the door cut-out.
Measure door thickness if choosing a telescopic or through-door product.
Decide whether you need an internal tidy.
Decide whether draught reduction or privacy is important.
Choose a style that suits the door: plain, decorative, postal knocker, vertical or telescopic.
Match the finish with nearby front door furniture.
Check what fixings are included before ordering.

Chrome letterbox FAQs

What size chrome letterbox do I need?

Measure the existing overall plate size, aperture size, fixing centres and door cut-out. If you are replacing an old letterbox, choose a size that covers the existing opening and lines up with the fixing points where possible.

What is the difference between a letterbox and a letter plate?

In many product names, the terms are used in a similar way. A letter plate usually refers to the flap or plate fitted to the door, while letterbox is often used more generally for the full post opening. Always check what is included with the product.

Do I need an internal letter tidy?

You need an internal tidy if you want to cover the inside cut-out, improve the hallway appearance or add an internal flap. It is especially useful when the inside of the opening looks rough or when replacing an older letterbox.

Will a chrome letterbox fit a uPVC door?

Some chrome letterboxes are suitable for uPVC doors, but many uPVC and composite doors need telescopic letterplates or specialist through-door products. Check the door thickness, fixing centres and product suitability before buying.

How do I stop draughts through a letterbox?

Choose an internal tidy with a draught excluder, a letterplate with a brush strip or seal, or a suitable telescopic design. Also check that the product is correctly fitted and that the flap closes properly.

Should my letterbox match my door knocker and numbers?

Matching the finish usually gives the best result. A chrome letterbox works well with chrome door numbers, chrome knockers, centre knobs, cylinder pulls and bell pushes, especially on dark painted or modern front doors.

Can I fit a larger letterbox than the old one?

Often, yes, provided the new fixing positions, aperture and door construction work with the replacement. A slightly larger plate can help cover old marks, but it still needs to operate correctly.