In England and Wales, you can use reasonable force to protect yourself or someone else, or to prevent a crime. A court asks two questions: was force necessary, and was the amount reasonable in the circumstances as you honestly believed them to be? You don’t have to wait to be hit first and there is no duty to retreat, but force after the danger has passed is not self-defence. Scotland and Northern Ireland have their own law.
Updated 16 October 2026 · Sources: legislation.gov.uk (Criminal Justice and Immigration Act 2008 section 76, Criminal Law Act 1967 section 3, Criminal Law Act (Northern Ireland) 1967 section 3), CPS legal guidance, CPS and NPCC householders statement, GOV.UK · Next review: January 2027
If you can get away safely, do that first and call 999. If you can’t speak, call 999 and follow the silent 999 call steps. The law protects reasonable self-defence, but getting to safety is always the better outcome.
The questions a court asks
What is the self-defence law in the UK?
In England and Wales, self-defence comes from the common law and section 3 of the Criminal Law Act 1967, which lets anyone use reasonable force to prevent crime or make a lawful arrest. Section 76 of the Criminal Justice and Immigration Act 2008 explains how “reasonable force” is judged. It also covers defending another person. Northern Ireland has its own 1967 Act; Scotland uses Scots common law.
What counts as reasonable force?
There is no fixed list. The law accepts that in the heat of the moment you can’t weigh the exact amount of force needed: if you only did what you honestly and instinctively thought necessary, section 76 says that is strong evidence you acted reasonably. Force that is disproportionate to the threat, or used for revenge or after the danger has passed, is not reasonable.
▲ likely within the law · ▬ depends on the facts · ▼ likely outside it. Examples from CPS guidance, the CPS and NPCC householders statement and GOV.UK; every case turns on its own facts. On carrying items, see what you can legally carry for self-defence and is pepper spray legal in the UK?
Do you have to retreat before defending yourself?
No. Section 76(6A) says there is no duty to retreat. Whether you could have got away is only one factor a court may weigh when deciding if your force was reasonable. In practice, getting away safely is still the best option: it keeps you out of danger and avoids any question about whether force was needed.
Can you hit someone first in self-defence?
Yes, in some situations. CPS guidance says there is no rule that a person must wait to be struck first. If you honestly believe an attack is about to happen, a reasonable pre-emptive response can be self-defence. But someone who starts the violence generally can’t rely on self-defence, and a planned confrontation counts against you.
What can you do if an intruder is in your home?
In a “householder case” in England and Wales, force against an intruder is judged more generously: only force that is grossly disproportionate is automatically unreasonable (section 76(5A)). This covers protecting yourself or others, not property, and only when you are inside the building and the intruder is, or you believe is, a trespasser. The CPS and police say: wherever possible, call the police.
Source: Criminal Justice and Immigration Act 2008 section 76(5A) and (8A)–(8F), CPS guidance. England and Wales.
If this happens, what should you do?
What should you do after using force in self-defence?
- Get to safety and make sure nobody is still in danger.
- Call 999 for police, and an ambulance if anyone is hurt, including the other person.
- Write down what happened as soon as you can: what you saw, heard and feared, and who else was there.
- Keep evidence: photos of injuries, damaged clothing, messages, CCTV or doorbell footage.
- Ask for legal advice before a formal police interview.
The CPS and police say simple cases can be closed quickly, and very few householders have ever been prosecuted for using force against intruders. If you were attacked, you are also a victim: see where to report a crime.
Is self-defence law the same in Scotland and Northern Ireland?
Not quite. Section 76 of the 2008 Act extends to England, Wales and Northern Ireland, and Northern Ireland has its own Criminal Law Act (Northern Ireland) 1967 with the same reasonable-force rule for preventing crime. Scotland is different: self-defence is a matter of Scots common law, section 76 does not apply, and the tests differ. In Scotland, ask Police Scotland or a Scottish solicitor.
▲ this guide · ▬ similar, separate law · ▼ different law. Checked on legislation.gov.uk on 16 October 2026. The CPS householders statement is written for England and Wales.
Related rights and the law
Self-defence is about force used at the moment of danger. Detaining someone afterwards is a different power: see citizen’s arrest in the UK. If you face repeated abuse or threats rather than a single attack, see harassment law in the UK and street harassment law. For what police can and can’t do if they stop you, see stop and search: your rights.
Frequently asked questions
Yes. In England and Wales, section 76 says self-defence includes acting in defence of another person. The same two questions apply: was force needed, and was the amount reasonable as you honestly saw the situation?
You can rely on a genuine belief even if it was mistaken. But you can’t rely on a mistake caused by being voluntarily drunk or high, and the less reasonable the belief, the less likely a court is to accept it was honestly held.
Picking up something to hand in the moment, especially at home, can be reasonable. Carrying a weapon or banned spray in public “just in case” can be a crime in itself, whatever happens later. See our guide to what you can legally carry.
Sources
- Criminal Justice and Immigration Act 2008, section 76
- Criminal Law Act 1967, section 3
- Criminal Law Act (Northern Ireland) 1967, section 3
- CPS: self-defence and the prevention of crime
- CPS and NPCC: householders and the use of force against intruders (2018)
- GOV.UK: using reasonable force against intruders
General information for the UK, not legal advice. Laws change: check GOV.UK or a solicitor for your situation. In an emergency, always call 999.
Keep reading
The best self-defence is not being alone with the danger
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