Can you tell a partner anonymously they need an STI test?

In the UK, letting partners know they may have been exposed to an STI is called partner notification, or contact tracing. It’s a standard part of STI care.

You can tell your partners yourself, or the service that treats you can usually contact them for you without naming you. This is often done by text. The message tells them they may have been exposed to an STI and should get tested, but it doesn’t mention your name.

Some online services also let you send an anonymous text or email. If you use one, check who runs it and what happens to your partner’s details.

Some people worry that a partner will think they’ve cheated. But many STIs cause no symptoms and can go unnoticed for a long time, so a diagnosis doesn’t always mean anyone has been unfaithful. Read more in “Can you get an STI in a relationship even if no one’s cheated?”

Many STIs cause no symptoms, so your partners may have an infection without knowing it. Telling them means they can:

• get tested, even if they feel fine
• get treated early, before the infection causes problems or is passed on to someone else
• avoid passing it back to you after your treatment

Partners are often infected. UK guidelines estimate that 46% to 60% of the partners of people with early Syphilis who can be contacted have it too. For Chlamydia, they estimate that between a third and two thirds of partners test positive.

Which partners you need to tell depends on the infection. UK guidelines suggest going back:

• Chlamydia: 6 months, or to 4 weeks before symptoms started for men with symptoms from the penis
• Gonorrhoea: 3 months, or to 2 weeks before symptoms started for men with symptoms from the penis (or your last partner, if that was longer ago)
• Syphilis: 3 months for the first stage, when there’s a sore, and up to 2 years or longer for later stages
• HIV: to 3 months before the time you were most likely infected
• Trichomonas: 4 weeks before you were diagnosed

If you’re not sure who to tell, the doctor or health adviser treating you can help you work it out.

Telling a previous partner that you have an STI is the right thing to do, but there’s no single right way to do it. Brook suggests:

• choosing a time and place where you feel safe and confident
• telling them face to face, or by message or voice note, whichever feels best for you
• starting by saying you have an STI, then giving them a chance to ask questions

You could say something like: “I’ve just found out I have Chlamydia. It often has no symptoms, so you might have it too. It’s treated with antibiotics, but you should get tested.”

If you don’t feel safe telling a partner, or you’re worried about how they’ll react, anonymous notification is there for exactly that reason.

Avoid vaginal, anal and oral sex until you and your partner have both finished treatment. For Gonorrhoea, UK guidance advises waiting until 7 days after you and your partners have finished treatment. Read more in “Should we get tested before having sex? How to talk to a new partner”

Finding out that a partner has an STI can be a shock, but it’s good that they told you, as it means you can get tested and treated early.

• Get tested, even if you feel fine, and tell whoever tests you which infection your partner has.
• You may be treated straight away or asked to wait for your result. UK guidance now usually tests the partners of people with Chlamydia or Gonorrhoea first, and treats them if the result is positive, unless they have symptoms. Partners of people with early Syphilis are either treated straight away or tested again 12 weeks after they last had sex with that person.
• Avoid sex until you know your result and have finished any treatment.

STI tests need time after sex to give a reliable result:

• Chlamydia and Gonorrhoea: from 2 weeks after sex
• HIV: from 45 days with a lab test
• Syphilis: a test in the first 3 months after sex can miss the infection, so you may need a repeat test

In England and Wales, there’s no legal requirement to tell a partner you have an STI. But passing on a serious infection intentionally or recklessly can be a crime.

The Crown Prosecution Service (CPS) can charge this as grievous bodily harm under the Offences Against the Person Act 1861. Cases have involved HIV and Herpes. For a charge of grievous bodily harm, the CPS has to prove the person actually passed the infection on.

If a partner knew about the infection and agreed to the risk, that can be a defence to reckless transmission, but not to intentional transmission. This is one more reason why being open with partners matters.

Someone with HIV who has an undetectable viral load can’t pass HIV on through sex, even without a condom.

Scotland and Northern Ireland have their own prosecution services. This is general information, not legal advice.

This post first reported in 2009 on inSPOT, a website that let people send an e-card to tell partners they might have been exposed to an STI. It was launched in San Francisco in 2004 by Internet Sexuality Information Services (ISIS), working with the city’s public health department, after Syphilis outbreaks were linked to meeting partners online.

Senders chose one of six e-cards and could send them anonymously. Each e-card linked to information about the infection, and the site had a map of local testing sites. By 2008, more than 30,000 people had sent over 49,500 e-cards, and about a quarter of the people who received one clicked through to the site. The team didn’t know how many went on to get tested.

inSPOT no longer runs, and its web address now redirects to ETR, a US health non-profit. In the UK, anonymous texts from sexual health services now do much the same job.

If a partner has told you they have an STI, or you want to check before telling anyone, Better2Know offers:

• Full Screen: tests for 7 infections, including Chlamydia, Gonorrhoea, HIV, Syphilis and Hepatitis B, from 28 days after sex, with results in 3 days (5 days for the home test). If you test before 45 days, a negative HIV result needs a repeat test. You can book it at one of our clinics or order a Full Screen home test.
• Peace of Mind: if you want to test sooner, it checks for Chlamydia, Gonorrhoea and Syphilis from 14 days after sex, with results in 2 days.
• Platinum Screen: our most comprehensive STI screen. It tests for 12 infections, adding Hepatitis C, Herpes 1, Herpes 2, Trichomonas and Gardnerella to the Full Screen, from 28 days after sex, with results in 3 days. If you test before 45 days, a negative HIV result needs a repeat test.

All three include a Syphilis test. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test. If you know which infection your partner has, our Patient Care Team can help you choose the right test. They’re available 24/7 on 020 7099 0955. If you test positive, we can help you with treatment or a referral.

Will an anonymous message name me?

No. An anonymous message says the person may have been exposed to an STI and should get tested, without saying who it’s from. If you’ve only had one or two recent partners, though, they may still guess.

Do I need to tell my ex?

If you had sex with them within the look-back period for your infection, yes. The NHS advises telling your current partner and any ex-partners, so they can get tested and treated too. You can tell them yourself or anonymously.

How soon should I tell a partner?

As soon as you can after your diagnosis. The sooner they know, the sooner they can get tested and treated, and the less likely they are to pass the infection on.

You don’t have to tell a partner face to face that you have an STI. In the UK, the service that treats you can usually let partners know anonymously, often by text. However they find out, telling partners means they can get tested and treated, and it helps stop the infection coming back to you.

If a partner has told you they have an STI, book a Full Screen at a clinic near you or order a home test kit from 28 days after sex. Our Patient Care Team is available 24/7 on 020 7099 0955.

Not in the UK? Choose your country from the selector at the top of the page for local tests and prices.

This article originally appeared on 8 February 2009 and was last updated on 30 September 2026.

This article is general information and not a substitute for personal medical advice.

Sources

1. NHS, Sexually transmitted infections (STIs), reviewed 13 May 2024. https://www.nhs.uk/conditions/sexually-transmitted-infections-stis/
2. Brook, How to tell someone you’ve got an STI, updated 21 August 2025. https://www.brook.org.uk/your-life/talking-to-people-about-stis/
3. McClean H, Radcliffe K, Sullivan A, Ahmed-Jushuf I. 2012 BASHH statement on partner notification for sexually transmissible infections. British Association for Sexual Health and HIV, 2012. https://www.bashh.org/resources/100/2012_bashh_statement_on_partner_notification_for_sexually_transmissible_infections
4. British Association for Sexual Health and HIV, National guideline for the management of infection with Chlamydia trachomatis, 2026. https://www.bashh.org/resources/174/chlamydia_guidelines_2026
5. British Association for Sexual Health and HIV, UK national guideline for the management of infection with Neisseria gonorrhoeae, 2025. https://www.bashh.org/resources/136/gonorrhoea_guideline_2025
6. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://bashh.org/_userfiles/pages/files/syphilis_2024.pdf
7. NHS, Chlamydia: treatment, reviewed 24 October 2024. https://www.nhs.uk/conditions/chlamydia/treatment/
8. NHS, Gonorrhoea: treatment, reviewed 16 December 2024. https://www.nhs.uk/conditions/gonorrhoea/treatment/
9. Crown Prosecution Service, Intentional or reckless sexual transmission of infection, updated 29 March 2023. https://www.cps.gov.uk/legal-guidance/intentional-or-reckless-sexual-transmission-infection
10. Levine D, Woodruff AJ, Mocello AR, et al. inSPOT: the first online STD partner notification system using electronic postcards. PLoS Medicine, 2008. https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0050213
11. British Association for Sexual Health and HIV, Summary guidance on testing for sexually transmitted infections, 2023. https://www.bashh.org/_userfiles/pages/files/resources/bashh_summary_guidance_on_stis_testing_2023.pdf
12. British HIV Association, British Association for Sexual Health and HIV and British Infection Association, Adult HIV testing guidelines, 2020. https://bhiva.org/wp-content/uploads/2024/10/HIV-testing-guidelines-2020.pdf