UK knife law has a reputation for being baffling, and to be fair, it has earned it. The rules are spread across at least five separate pieces of legislation, some of it dating back to 1953, amended repeatedly, and written in language that does not always match how normal people describe knives.
The good news is that once you separate the three questions the law actually asks, it becomes fairly straightforward. Those questions are:
- Can I own this?
- Can I carry it in public?
- Can I buy it, and how?
They have different answers, and most of the confusion out there comes from people mixing them up. A knife can be perfectly legal to own and still land you in serious trouble in your coat pocket on a Tuesday afternoon.
Here is the whole thing, plainly.
The single most important distinction: owning versus carrying
Start here, because it clears up most of it.
Owning a knife at home is legal for the overwhelming majority of knives. Kitchen knives, hunting knives, fixed blades, collectors' pieces, replica blades, swords - all legal to own, keep and display in your own home. There is a short list of exceptions, covered below, but the default is that ownership is fine.
Carrying a knife in public is where the law gets strict. Under section 139 of the Criminal Justice Act 1988, it is an offence to have any article with a blade or sharp point in a public place. Not "a dangerous knife". Any blade. The burden then falls on you to show a good reason for having it.
There is exactly one blanket exception, and it is narrower than most people think.
The pocket knife exception (and the trap inside it)
You may carry, without needing any particular reason, a folding pocket knife with a cutting edge of 3 inches (7.62cm) or less.
That sounds generous. Then comes the trap:
"Folding" means it must not lock.
If the blade locks open - even with a two-inch blade, even a perfectly ordinary work knife - it is not a folding pocket knife in the eyes of the law. The courts settled this, and a locking knife is treated exactly like a fixed blade. You would need a good reason to have it in public.
This catches out an enormous number of otherwise entirely law-abiding people, because locking knives are safer to use and are sold everywhere for legitimate work. The law does not care that the lock is a safety feature. If it locks, the automatic exemption does not apply.
So: non-locking, under 3 inches, carry freely. Anything else, including any locking knife, needs a reason.
What counts as a "good reason"?
The law calls it "good reason or lawful authority", and it is decided case by case. Reasons that are generally accepted:
- Work. A chef carrying knives to a shift, a carpet fitter with a trimming knife, a fisherman with a gutting knife.
- Religious observance. The Sikh kirpan is expressly recognised.
- National costume. The sgian-dubh worn with Highland dress.
- Historical re-enactment, martial arts and theatrical use. Transporting a blade to and from a class, event or production.
- Taking it home from the shop. Reasonably, and promptly - a receipt helps.
Reasons that are not good reasons, no matter how sincerely held:
- Self-defence. This is worth stating flatly: carrying a knife for self-defence is not a defence in UK law. It never has been.
- "I forgot it was in my bag."
- "It's only a small one."
- "I use it for fishing" - said while not going fishing.
The practical test is whether the knife's presence makes sense for what you are actually doing at that moment. If you are taking a blade somewhere for a genuine purpose, wrap it, put it out of reach, keep any paperwork, and do not detour to the pub.
Knives that are banned outright
This is the short list where ownership itself is an offence - not just carrying. Possessing these, even privately at home, is illegal. Under section 141 of the Criminal Justice Act 1988 and the Restriction of Offensive Weapons Act 1959, the banned list includes:
- Flick knives (switchblades, automatic knives) - blades that open by a button, spring or pressure on the handle
- Gravity knives
- Butterfly knives (balisongs) - see the section below, because this one has a legal exception that matters
- Disguised knives - blades hidden in belt buckles, lipsticks, phones, combs
- Push daggers
- Stealth knives - non-metallic blades designed to defeat detection
- Zombie knives and zombie-style knives
- Machetes
- Ninja swords - added to the banned list on 1 August 2025, and covered in its own section below
- Cyclone and spiral knives
- Sword-sticks
- Plus a set of related weapons: knuckledusters, telescopic truncheons, blowpipes, shurikens or "death stars", kusari-gama, kyoketsu-shoge, hand and foot claws
Curved swords with a blade over 50cm also sit under section 141, restricted since April 2008. But the defences here are broad and genuinely useful to collectors. The restriction does not bite where the sword was made before 1954, or made according to traditional methods of making swords by hand, or is held for a permitted activity such as historical re-enactment or a sporting activity, or is used for religious ceremonies.
There is one more defence that catches a lot of people out, and it is the one that matters most to collectors: a blunt sword has a defence. In law, "blunt" means the piece has no thin edge adapted to cutting, no sharp point adapted to piercing, and no other element adapted to cutting or piercing. A genuine display sword built to hang on a wall meets that description.
That is why hand-forged katanas are legal to buy in the UK on the traditional-forging basis, and why our display katanas sit on a different footing from our hand-forged range. If you are buying a curved sword over 50cm, the question to ask the retailer is which defence the piece relies on. A retailer who cannot answer that is one to avoid.
Ninja swords - banned since August 2025
This is the newest addition to the banned list and the one most likely to catch out anyone working from older guidance. Ninja swords became prohibited weapons under section 141 on 1 August 2025, following the campaign in memory of Ronan Kanda, and the change is generally referred to as Ronan's Law.
The legal description is precise rather than a matter of vibes. A "ninja sword" is a sword with:
- a blade at least 14 inches but no more than 24 inches long
- a primary straight cutting edge
- a secondary straight cutting edge
- a blunt spine, and
- either a tanto style point or a reversed tanto style point
All of those have to be present. A blade shorter than 14 inches or longer than 24 is not a ninja sword for these purposes, and neither is a straight blade with a conventional point.
The same defences that apply elsewhere apply here: the sword is blunt, or it was made by hand, or it is of historical importance, or it is held for a permitted activity such as re-enactment or a sporting activity.
The practical upshot for collectors is that a blunt display piece is on a different footing from a sharpened one, but the description is tight enough that it is worth measuring before you assume. If you own something that might fall inside it, check the blade length and the point profile rather than guessing.
The butterfly knife question
Butterfly knives are banned. So why can you buy a balisong trainer?
Because the ban applies to bladed butterfly knives. A balisong trainer has no cutting edge at all - the "blade" is a blunt, unsharpened piece of metal, usually with a rounded or squared-off profile, made for practising the flipping technique. With no cutting edge and no point, it is not a knife in the sense the legislation means.
They are legal to own and buy, they are genuinely good fun, and they are how anyone sensible learns balisong manipulation without removing a fingertip. Our balisong trick trainers are exactly this: unsharpened trainers.
To be completely clear: a sharpened butterfly knife is a banned offensive weapon, and modifying a trainer to give it an edge would turn a legal item into an illegal one. Do not do that. Also worth knowing that a trainer still looks unmistakably like a butterfly knife, so flipping one in public is likely to generate a conversation with someone in a uniform that neither of you will enjoy.
Buying knives online
Two rules govern this, and both fall on the retailer as much as the buyer.
Age verification. It is an offence to sell most knives and bladed products to anyone under 18. Any legitimate UK seller will verify your age. If a site sells you a blade without doing so, that tells you something about the rest of their compliance.
Delivery restrictions. Under the Offensive Weapons Act 2019, there are restrictions on delivering bladed products to residential addresses following a remote sale. Sellers have to have specific arrangements in place, and there are conditions and exemptions - including for bespoke and made-to-order items, and for sales to businesses.
In practice this is why buying a blade online involves more steps than buying a kettle: age checks at checkout, sometimes age checks again at the door, and occasionally a delivery method you did not expect. It is not the retailer being awkward. It is the retailer staying legal.
What is coming next. The Crime and Policing Act 2026 received Royal Assent on 29 April 2026 and will tighten this considerably once its knife provisions are brought into force. Buyers will need to provide photographic ID and a matching photograph of themselves at the point of purchase, and show ID again to the courier on delivery. Retailers will also have to report bulk orders - six or more knives from the same buyer or to the same address within 30 days - to the police. Those measures are not yet in force and await further commencement regulations, so nothing has changed for you today. But they are coming, and any retailer worth buying from is already preparing for them.
At The Sword Stall, new customers complete age verification once, before their first order is dispatched. It takes a couple of minutes and then it never troubles you again. Everything we sell is held in our own warehouse in Bacup, Lancashire, which means we control the dispatch process rather than hoping a third party somewhere else handles it correctly.
Quick reference
| Knife | Own at home | Carry in public |
|---|---|---|
| Non-locking folding knife, under 3in | Legal | Legal, no reason needed |
| Locking folding knife, any size | Legal | Needs good reason |
| Fixed blade of any length | Legal | Needs good reason |
| Kitchen knives | Legal | Needs good reason |
| Throwing knives | Legal | Needs good reason |
| Hand-forged katana | Legal | Needs good reason |
| Blunt display sword, curved, over 50cm | Legal - bluntness defence | Needs good reason |
| Sharpened curved sword over 50cm, not hand-forged | Illegal unless another defence applies | Illegal |
| Ninja sword, blunt | Legal - bluntness defence | Needs good reason |
| Ninja sword, sharpened (14-24in, tanto point) | Illegal | Illegal |
| Balisong trainer (no edge) | Legal | Inadvisable |
| Butterfly knife (sharpened) | Illegal | Illegal |
| Flick knife / switchblade | Illegal | Illegal |
| Zombie-style knife | Illegal | Illegal |
| Machete | Illegal | Illegal |
| Disguised knife | Illegal | Illegal |
What this means if you collect
None of the above should put you off collecting. The overwhelming majority of collectors' pieces are entirely legal to own, and the law is aimed squarely at people carrying weapons in the street rather than people mounting blades on a wall.
The practical rules for collectors come down to four things. Buy from a UK retailer that does age verification properly. Keep your collection at home. Transport pieces wrapped, unloaded of any purpose, and only when you have a genuine reason. And know which side of the banned list a piece sits on before you buy it, not after.
Browse our knives collection, our tanto range, our daggers and the full replica swords range. For event and convention use where metal is not permitted, our cosplay weapons collection covers the same designs in event-safe foam.
Frequently asked questions
What size knife is legal to carry in the UK?
A folding pocket knife with a cutting edge of 3 inches (7.62cm) or less can be carried without needing a specific reason - but only if it does not lock. Locking knives, regardless of blade length, are treated the same as fixed blades and require a good reason. Any other blade in a public place requires good reason or lawful authority.
Is it legal to own a knife in the UK?
Yes, for almost all knives. Fixed blades, locking knives, kitchen knives, collectors' pieces and swords are all legal to own and keep at home. A short list of weapons is banned outright even in private, including flick knives, sharpened butterfly knives, zombie-style knives, machetes, ninja swords, push daggers and disguised knives.
Are butterfly knives legal in the UK?
Sharpened butterfly knives are banned outright - it is an offence to own, sell or import one. Unsharpened balisong trainers with no cutting edge are legal, because the ban applies to bladed articles and a trainer has no blade. Modifying a trainer to give it an edge would make it illegal.
Can I carry a knife for self-defence?
No. Carrying a knife for self-defence is not a good reason under UK law and has never been accepted as one. Doing so is an offence regardless of whether you ever use it.
Are swords legal in the UK?
Yes, with two restrictions to know about. Owning a sword at home is legal. Since 2008 it has been an offence to sell, import, manufacture or possess a curved sword with a blade over 50cm, and since 1 August 2025 the same applies to ninja swords. Both restrictions carry broad defences - a sword made before 1954, made by hand using traditional methods, held for a permitted activity such as re-enactment or sport, or that is blunt. That last one covers most display pieces, which is why a great many collectors' swords are entirely lawful.
Are ninja swords legal in the UK?
Not since 1 August 2025, when they were added to the banned weapons list under what is generally called Ronan's Law. The legal description is specific: a blade at least 14 but no more than 24 inches, a primary straight cutting edge, a secondary straight cutting edge, a blunt spine, and a tanto or reversed tanto style point. All of those elements have to be present. Defences apply where the sword is blunt, made by hand, of historical importance, or held for a permitted activity such as re-enactment or a sporting activity.
What is Ronan's Law?
The common name for the ban on ninja swords that took effect on 1 August 2025, introduced after the murder of 16-year-old Ronan Kanda in Wolverhampton in 2022. It added ninja swords to the list of weapons prohibited under section 141 of the Criminal Justice Act 1988, and was preceded by a national surrender scheme.
Do I need to be 18 to buy a knife in the UK?
Yes. It is an offence to sell most knives and bladed products to anyone under 18, and legitimate retailers verify age at the point of sale. There are also restrictions on delivering bladed products to residential addresses after an online sale, which is why buying a blade online involves extra verification steps.
Are throwing knives legal in the UK?
Yes, throwing knives are legal to own and to buy if you are over 18. They are not covered by the banned weapons list. Carrying them in public requires a good reason - transporting them to a range or a class is fine, provided they are properly wrapped and you are actually going there.
This article is general guidance, not legal advice, and reflects the law in England and Wales as at August 2026. Knife legislation is amended regularly. If you are unsure whether a specific item is lawful in your circumstances, check the current position on GOV.UK or take proper legal advice.
