A letterbox is one of the smallest bits of hardware on your house, and one of the most annoying when it goes wrong. A flap that bangs in the wind keeps people awake, lets cold air straight into the hallway, and — if it's hanging open — makes the front door look like an invitation.
The instinct is to order a new letter plate. Most of the time you don't need one. This guide walks through the common letterbox faults, how to tell which one you've got, and when a replacement genuinely is the better answer. It starts with a real job.
A storm call-out: the flapping front door
When Storm Austen — the first named storm of the 2026/27 season — came through in late October, we got a call from the owner of a short-let property in Dartford. The guests had complained about a constant flapping noise near the front door, and the owner wanted someone to inspect before it turned into a bad review.
The guests were out sightseeing when we arrived, which gave us a clear run at the door. We checked the whole exterior first — fascias, guttering, the canopy, anything loose that could be catching the wind. Everything else was sound. The noise was coming from the letter plate on the composite front door: the external flap had worked loose from its fixings and was hanging at an angle, so every gust lifted it and slammed it back down.
Up close, the cause was obvious. The bolts that clamp the outer plate to the inner frame through the door had loosened, letting the outer plate drop out of position. The draught brush on the inside had also frayed where the flap had been chewing at it.
None of that needed a new letter plate. We picked up the correct fixing screws, fed them through the inner frame on the back of the door into the outer plate so it was pulled back tight and square, and re-bonded the frayed section of the draught brush so it sat flat again. Then we worked the flap open and closed repeatedly to make sure it closed cleanly, sealed against the brush, and didn't rattle. Total time on site was short, and the door was fixed before the guests came back.
The point isn't that this was a clever repair. It's that it was the right one. A new letter plate would have cost more, taken longer to source in the correct size for a composite door, and sent a perfectly serviceable piece of hardware to landfill.
How we approach every small repair
That job sums up how we work on everything, not just letterboxes:
- Understand the problem first. Find the actual cause, not just the symptom. A flapping noise could be the letterbox, a loose fascia, a gate, or a downpipe bracket.
- Recommend a fix. Repair from first principles where the part is sound; replace only where it isn't.
- Get approval. No work starts until the owner agrees.
- Fix it before we leave. Wherever possible, the job is done on the same visit — no second trip, no waiting on parts that weren't needed.
Sustainability isn't a slogan here. It's simply what happens when you repair before you buy.
How a letter plate works
Knowing the parts makes diagnosis much easier. A typical UK letter plate has:
- An outer plate and flap — the visible part on the outside of the door, usually spring-loaded or gravity-hung.
- An inner frame — on the inside face of the door, sometimes with its own flap.
- Fixing bolts or screws — these pass through the door from the inside and screw into threaded bosses on the back of the outer plate, clamping the two halves together.
- A sleeve (on composite and uPVC doors) — a telescopic liner that runs through the aperture so post doesn't snag on the door core. Sleeves are adjustable to suit different door thicknesses.
- A draught excluder — usually a brush strip or rubber fingers on the inside, sometimes a separate internal flap.
Most faults come down to one of three things: the fixings, the spring or hinge, or the draught seal.
Common letterbox problems — repair or replace?
Usually a repair. The flap is either loose on its fixings, or the spring that holds it shut has weakened. Tighten the fixing bolts from the inside first — that alone solves a surprising number of cases. If the flap is still lifting in gusts, a stiffer spring or an internal flap or brush excluder will stop the wind getting purchase on it.
Usually a repair — exactly the Dartford job. When the outer plate drops out of line, it's almost always because the clamping bolts have loosened or been lost. Re-fixing with the correct screws pulls it back square. Check the threaded bosses on the back of the outer plate aren't stripped; if they are, that's when replacement starts to make sense.
Repair, if the spring is the problem. Springs fatigue, corrode, or jump off their mounting. On many plates they can be reseated or replaced. If the hinge pin itself has worn or snapped on a cheap plate, a replacement is often quicker and costs about the same.
Repair. A letterbox is a hole in your door's insulation, and a worn brush strip lets a surprising amount of heat out. Replacement brush excluders are cheap and generic; most fit standard apertures. If the brush is only partly frayed, bonding it back down buys time; once it's thin and gappy, a new one is the better fix. The Energy Saving Trust's guidance on draught-proofing covers letterboxes alongside doors and windows. Our winter maintenance checklist lists it as one of the cheapest wins in the house.
Repair or adjust. On composite and uPVC doors this usually means the sleeve has shifted or wasn't sized to the door thickness. Adjusting or replacing the sleeve fixes it without touching the plate.
Replace. Once the plate itself is cracked, the threaded bosses have stripped, or the finish has corroded through, there's nothing sound left to repair. Cheap zinc-alloy plates are the usual culprits — the chrome finish pits, the metal underneath crumbles, and screws won't hold.
Consider upgrading. Older letter plates can allow “letterbox fishing” — reaching through to hook keys or turn a thumb-turn lock from outside. The industry answer is the TS 008 specification, developed by the Door & Hardware Federation, which tests letter plates against fishing, lock manipulation and forced removal. TS 008 plates are referenced in Approved Document Q, which covers security in new homes in England, and in the police-backed Secured by Design scheme. There's no legal requirement to fit one on an existing home, but if your door has a thumb-turn lock near the letterbox, or keys are kept in the hallway, it's a sensible upgrade.
Quick decision table
| Problem | Verdict | Typical fix |
|---|---|---|
| Flap banging in the wind | Repair | Tighten fixings, stiffer spring, add excluder |
| Flap hanging loose or crooked | Repair | Re-fix outer plate with correct screws |
| Flap stuck open | Repair (usually) | Reseat or replace spring |
| Draughts through the letterbox | Repair | Re-bond or replace brush excluder |
| Post snagging | Repair | Adjust or replace sleeve |
| Stripped fixing bosses | Replace | New letter plate |
| Cracked or corroded plate | Replace | New letter plate |
| Thumb-turn lock near letterbox | Upgrade | TS 008 security letter plate |
| Fire door letter plate damaged | Replace like-for-like | Fire-rated plate to suit the door's certification |
A note on fire doors and flats
If the letterbox is on a fire door — common on flat entrance doors in purpose-built blocks — don't improvise. The letter plate is part of the door's fire certification, and a non-rated replacement or a botched repair can compromise it. In blocks of flats, the responsible person for the building has duties under the Fire Safety (England) Regulations 2022 around checking flat entrance doors. Speak to the building manager before any work. Our door repair or replacement guide covers fire doors in more detail.
What a letterbox repair typically costs
Prices vary by region and by door type, but as a guide:
- Re-fixing a loose plate or tightening a flapping flap: usually a small-job visit, typically £60–£100.
- Replacing a brush draught excluder: parts around £8–£25, plus fitting.
- Replacing a standard letter plate: parts £15–£40; fitted, typically £80–£140.
- Upgrading to a TS 008 security letter plate: parts £40–£100; fitted, typically £120–£200.
- Composite door with sleeve replacement: add £20–£50 for the sleeve.
We work on flat-rate pricing, so you know the cost before we start rather than watching the clock. For a full framework on weighing up repair against replacement, see our repair or replace guide.
For landlords and short-let hosts
A rattling letterbox is a small fault with an outsized effect on a short-let. Guests notice noise and draughts, and they mention them in reviews. A quick inspection after any named storm — letter plate, door seals, fascias, gates, anything that can flap — catches these before a guest does. If you manage properties at a distance, it's worth having someone who will diagnose and fix on the same visit rather than quote and come back. Our handyman services cover exactly this kind of reactive job.
Frequently asked
Why does my letterbox flap bang in the wind?
Usually because the flap's fixings have loosened or its spring has weakened, so wind pressure can lift it. Tightening the fixing bolts from inside the door fixes most cases; adding an internal brush or flap stops the wind reaching it.
Can I fix a broken letterbox myself?
Simple faults — loose fixings, a dislodged brush strip — are often DIY-friendly with a screwdriver and the right screws. Take the old screws to a merchant to match the length and thread. Composite doors, fire doors and security upgrades are better left to someone who fits them regularly.
How do I stop draughts coming through my letterbox?
Fit or replace a brush draught excluder on the inside of the door. Generic brushes fit most standard apertures and are inexpensive. An internal flap adds a second seal.
What is a TS 008 letterbox?
A letter plate certified to the TS 008 specification from the Door & Hardware Federation, which tests resistance to letterbox fishing, lock manipulation and forced removal. It's the standard referenced by Secured by Design and in Approved Document Q for new homes.
Do composite doors need a special letterbox?
They need a letter plate with a sleeve that matches the door's thickness — typically around 44mm to 48mm, though it varies. Measure before buying, or the plate won't clamp properly.
Should I replace my letterbox after a storm?
Not automatically. Storm damage to letterboxes is usually loosened fixings or a bent flap, both of which are repairable. Replace only if the plate is cracked, the threads are stripped, or the spring mechanism has failed beyond repair.