HIV, sex and the law

Mareike Günsche |

Key points

  • This page covers the criminalisation of HIV transmission in England, Wales and Northern Ireland. The law in Scotland is different.
  • A person may be charged if their sexual partner acquires HIV through condomless sex without HIV status having been discussed.
  • Nonetheless, there is no legal obligation to disclose HIV status or to use a specific prevention method, so long as transmission doesn’t occur.

In England, Wales and Northern Ireland, it is possible you could have legal action taken against you. This will only happen if all of the following apply:

  • You suspect or know you are HIV positive
  • You suspect or know you have a detectable viral load
  • You still have sex without a condom without telling your sexual partner about your HIV status
  • Your partner acquires HIV as a result.

This issue may affect how you approach your sex life after an HIV diagnosis.

Several people in England, Wales and Northern Ireland have been charged with committing an offence because their sexual partners acquired HIV through sex without a condom, and they had not told them they were HIV positive. (The term often used in the law is ‘reckless’ transmission.)

In England and Wales there is no legal obligation to disclose your HIV status to a sexual partner, but if you are later charged with transmitting HIV, proving that your partner knew you were HIV positive would help your defence.

If you take precautions to protect your sexual partner from HIV by using a condom or ensuring your viral load is undetectable by adhering to treatment, it is extremely unlikely you would be charged with reckless transmission.

If your partner knows you have HIV and consents to sex without a condom, do not assume that they are also HIV-positive or on PrEP (regular medication to prevent HIV infection), as you may be charged for any resulting infection if your partner goes to the police. In those rare circumstances, proving that they consented to the risk would help your defence.


undetectable viral load

A level of viral load that is too low to be picked up by the particular viral load test being used or below an agreed threshold (such as 50 copies/ml or 200 copies/ml). An undetectable viral load is the first goal of antiretroviral therapy.

viral load

Measurement of the amount of virus in a blood sample, reported as number of HIV RNA copies per milliliter of blood plasma. Viral load is an important indicator of HIV progression and of how well treatment is working. 



A micro-organism composed of a piece of genetic material (RNA or DNA) surrounded by a protein coat. To replicate, a virus must infect a cell and direct its cellular machinery to produce new viruses.


post-exposure prophylaxis (PEP)

A month-long course of antiretroviral medicines taken after exposure or possible exposure to HIV, to reduce the risk of acquiring HIV.

Undetectable = Untransmittable (U=U)

U=U stands for Undetectable = Untransmittable. It means that when a person living with HIV is on regular treatment that lowers the amount of virus in their body to undetectable levels, there is zero risk of passing on HIV to their partners. The low level of virus is described as an undetectable viral load. 

In Scotland, the law is different. As well as the possibility of being charged for passing on HIV in those circumstances, it is possible to be prosecuted for putting another person at risk of HIV infection, even if they don’t become HIV positive. (The term used for this in the law is ‘reckless endangerment’ or ‘reckless exposure’.)  As in England and Wales, proving that you disclosed your HIV status to your partner and they consented to the risk would help your defence.

Most cases come about because someone has made a complaint. This was usually because they feel they didn’t have all the information to protect themselves from HIV and/or because they feel deceived or betrayed in some way.

Around 30 people have been convicted and sent to prison in the UK. There have been more arrests and investigations, some of which have lasted for many months, even in cases which didn’t go to court. They have had a serious impact on the lives of both the accused and the people making the complaint.

The Crown Prosecution Service (for England and Wales) has produced guidance to help the courts decide if a crime has been committed and whether someone should be charged. The Crown Office and Procurator Fiscal Service in Scotland has done the same. The Association of Chief Police Officers has also published guidance. These guidelines say that there is usually no case if:

  • you didn’t know, or suspect, you have HIV or
  • you can prove you told your partner you are HIV positive and
  • you took reasonable steps to avoid passing HIV on to your partner.

Lawyers think that if you use condoms every time you have sex, and for the entire duration of sex, you would have a good defence if transmission did occur.

The Crown Prosecution Service guidance states that the medical consensus is that anyone with undetectable levels of HIV virus in their blood at the time of sex cannot transmit HIV to their sexual partners. If you have a sustained undetectable viral load and are aware that Undetectable = Untransmittable (U=U), this should be considered reasonable action to prevent HIV transmission.

But neither of these defences have been tested in a court of law.

The law is also not clear on your liability if you use a condom and you notice that it breaks or comes off. Advice is that you should tell your partner that you have HIV if they do not already know and advise them to seek treatment called post-exposure prophylaxis (PEP). This is where a short course of HIV treatment is given (within 72 hours) to prevent HIV infection after someone has been exposed to the virus.

Ultimately, it is your decision when and whether to tell your sexual partners that you have HIV. You may want to consider whether the kind of sex you are having involves a substantial risk of HIV transmission. Anal and vaginal sex without a condom have the highest risk, while oral sex is extremely low risk. Properly used condoms can provide effective protection.

Often HIV-negative people (or those who don’t know their status) expect people with HIV to tell them before they have sex. They will then assume that, because there has been no mention of HIV and they have had sex without using a condom, their partner is also HIV negative.

Just as people living with HIV have a responsibility to look after their own health and not to pass on HIV, HIV-negative people and people who don’t know their HIV status have a responsibility to look after their own health and to protect themselves from HIV. But, in the eyes of the law, the balance of responsibility is weighted more towards people with HIV.

If you are being investigated, or you think that someone may make a complaint against you, it’s important you get good advice and support from an HIV support organisation. You need to find an experienced lawyer straight away, before you make any statement to the police. In the UK, the Terrence Higgins Trust helpline, THT Direct, can help you find both these; you can speak to them in confidence on 0808 802 1221. You may also want to speak to THT Direct or another support organisation if you are thinking of making a complaint.

You can find more useful information on the Terrence Higgins Trust website.

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