Grievous bodily harm in the UK is the offence of inflicting “really serious harm” on another person, prosecuted under the Offences Against the Person Act 1861 in England, Wales, and Northern Ireland. It comes in two forms: Section 18, where the attacker intended serious injury, carries a maximum of life imprisonment; Section 20, where they did not, carries up to five years in England and Wales and seven years in Northern Ireland.1The Crown Prosecution Service. Offences against the Person, incorporating the Charging Standard Scotland uses a different framework and is addressed briefly at the end.
What Counts as Really Serious Harm
The 1861 Act does not define grievous bodily harm. The working test comes from DPP v Smith (1961), which read the phrase as “really serious harm,” and courts have applied that standard ever since. Whether an injury crosses the line is a question of fact: the nature of the injury, the treatment required, and the effect on the victim’s life.1The Crown Prosecution Service. Offences against the Person, incorporating the Charging Standard
That assessment takes the victim as they are. An injury that a healthy adult would shake off may be life-threatening to a child or an elderly person, and the law treats it accordingly. The CPS charging guidance flags life-changing injuries and cases needing significant or sustained medical treatment, including intensive care, blood transfusions, or multiple surgeries, as the type of harm that typically qualifies, even where the victim eventually recovers fully.1The Crown Prosecution Service. Offences against the Person, incorporating the Charging Standard
Injuries that regularly result in GBH charges include:
- Broken bones, particularly compound fractures or fractures needing surgical repair
- Skull fractures, traumatic brain injuries, or any injury causing lasting cognitive impairment
- Internal organ damage such as a ruptured spleen or collapsed lung
- Permanent disfigurement, including deep scarring or loss of teeth
- Loss of sensory function or a limb
Both sections also cover “wounding,” which has a narrower legal meaning: the full thickness of the skin must be broken, both the epidermis and the dermis. A deep cut qualifies. A bruise or internal bleeding does not, however serious. That opens a second route to conviction: a knife slash that heals quickly is still a wound, even if the injury itself would not meet the “really serious harm” threshold.
Psychological injury can amount to GBH, but only where expert psychiatric evidence establishes a recognised psychiatric illness. The House of Lords set this as a threshold question in R v Burstow. Anxiety and sleeplessness alone, without a diagnosis linked to the defendant’s conduct, will not do it, and cases in this category often fail on the evidence.
Section 18 or Section 20: Where the Intent Line Sits
The injuries under the two sections can look identical. The difference is what the prosecution has to prove about the defendant’s state of mind.
Section 18: GBH With Intent
Section 18 requires proof that the defendant intended to cause really serious harm, or that they wounded or caused GBH while resisting or preventing a lawful arrest.2Legislation.gov.uk. Offences Against the Person Act 1861 – Section 18 Prosecutors need to show the defendant set out to do real damage, not simply that a punch landed badly. Weapon use, repeated blows to vulnerable parts of the body, or prior threats are the kind of evidence that can establish intent.
Section 18 is indictable-only, so it is tried in the Crown Court, and the maximum is life imprisonment.1The Crown Prosecution Service. Offences against the Person, incorporating the Charging Standard
Section 20: GBH Without Intent
Section 20 catches cases where someone causes really serious harm without specifically intending that level of injury. The prosecution only has to prove the defendant acted “maliciously,” which in practice means either intending some physical harm or being reckless about whether harm would result.3Legislation.gov.uk. Offences Against the Person Act 1861 – Section 20 A single punch that fractures a skull can fall under Section 20 if the attacker foresaw that some harm was possible, even if the outcome was far worse than they imagined.
Section 20 is an either-way offence, triable in the Magistrates’ Court or the Crown Court depending on seriousness. The maximum is five years’ imprisonment in England and Wales, and seven years in Northern Ireland.3Legislation.gov.uk. Offences Against the Person Act 1861 – Section 20
Where Racial or Religious Motivation Applies
A Section 20 offence motivated by racial or religious hostility becomes a separate, more serious offence under Section 29 of the Crime and Disorder Act 1998, with the maximum rising from five to seven years.4Legislation.gov.uk. Crime and Disorder Act 1998 – Racially or Religiously Aggravated Offences: England and Wales The prosecution has to show the defendant demonstrated hostility based on race or religion during the offence, or was motivated by it. Section 18 has no separate aggravated version because life imprisonment is already available, but the same motivation counts as an aggravating factor at sentencing.
Sentences You Could Face
Judges work from Sentencing Council guidelines that build a matrix from the offender’s culpability and the harm caused, then adjust for aggravating and mitigating factors.
For Section 18, the sentencing range runs from 2 to 16 years’ custody. The worst cases, combining high culpability with the most serious injuries, have a starting point of 12 years. Mid-range cases start around 7 years, and lower culpability cases around 5. Life imprisonment remains available for the most extreme circumstances.5Sentencing Council. Causing Grievous Bodily Harm with Intent to Do Grievous Bodily Harm / Wounding with Intent to Do GBH
Section 20 sentences are much lower. Starting points range from a low-level community order at the bottom of the scale up to around four years’ custody at the top, with fines and suspended sentences also available for lower-harm, lower-culpability offences. Every adult convicted also pays a mandatory victim surcharge on top of any other sentence.
Common aggravating factors include using a weapon, targeting a vulnerable victim, committing the offence while on bail, and prior convictions for violence. Mitigating factors include genuine remorse, no previous convictions, provocation, and mental health issues that contributed to the offending.
Defences That Actually Work
The most commonly raised defence is self-defence. There is no fixed formula for what counts as reasonable force: it depends on the circumstances as the defendant honestly believed them to be at the time.6GOV.UK. Using Reasonable Force Against Intruders If a jury accepts that the defendant genuinely believed they were under threat and used no more force than seemed necessary, the result is a full acquittal. The defence falls apart when the force was clearly disproportionate, such as continuing to beat someone who is already on the ground and no longer a threat.
Consent is generally not a defence to GBH. In R v Brown (1994) the House of Lords held that a person cannot consent to the infliction of serious harm, and the Domestic Abuse Act 2021 reinforced the principle by ruling out any argument that a victim consented to serious harm for sexual gratification.7GOV.UK. Consent to Serious Harm for Sexual Gratification Not a Defence Narrow exceptions exist for properly conducted sporting activities and legitimate medical procedures, where participants accept certain inherent risks.
Life After a GBH Conviction
A conviction reaches beyond the sentence itself. It sits on your criminal record and can affect employment, housing, and personal relationships for years.
Under the Rehabilitation of Offenders Act 1974, most convictions eventually become “spent,” meaning they no longer have to be disclosed for standard job applications. The rehabilitation period depends on the length of sentence. Government guidance shows that even a Section 18 conviction can become spent where the sentence is short enough: in one published example, a three-year sentence became spent seven years after the conviction date.8GOV.UK. Rehabilitation Periods Sentences over four years never become spent, and because Section 18 cases often exceed that threshold, many GBH convictions stay on the record permanently for disclosure purposes.
A spent conviction still has to be disclosed for sensitive roles that require enhanced DBS checks, including work with children, healthcare, law enforcement, and financial services.
International travel is another practical consequence. The United States can refuse a visa to anyone convicted of a “crime involving moral turpitude,” and U.S. immigration guidance explicitly lists assault with intent to cause serious bodily harm as a crime normally considered to involve moral turpitude.9U.S. Department of State. Ineligibility Based on Criminal Activity, Criminal Convictions and Related Activities – INA 212(a)(2) A Section 18 conviction would almost certainly fall in scope; a Section 20 conviction may or may not, depending on how the consular officer views the facts. Canada and Australia also restrict entry for people with serious violent convictions.
Scotland Uses a Different Framework
GBH is not a recognised offence in Scotland. Scottish criminal law handles violent offences through the common law crime of assault, graded by severity. What would be charged as GBH south of the border is typically prosecuted as “serious assault” in Scotland: an assault causing injuries requiring hospital admission, fractures, internal injuries, severe concussion, loss of consciousness, or lacerations likely to cause impairment or disfigurement. Sentencing is handled under Scottish guidelines, and anyone facing charges there needs advice specific to Scots law.