Chlamydia Partner Notification: Who to Tell and How
Key fact: Studies show approximately 1 in 6 people treated for chlamydia is reinfected within 12 months—almost always because a sexual partner was not tested and treated. Partner notification is the single most effective way to break this cycle.
6
months lookback period recommended by BASHH 2025 guidelines
~50%
of chlamydia cases have no symptoms, meaning partners may be unaware
3
months post-treatment — recommended retesting window to catch reinfection
Why Partner Notification Matters
Partner notification—sometimes called contact tracing or partner referral—is the process of informing recent sexual partners that they may have been exposed to chlamydia. It is a central part of the clinical management of chlamydia and is recommended by the British Association for Sexual Health and HIV (BASHH) 2025 guidelines.
Chlamydia is caused by the bacterium Chlamydia trachomatis and is the most commonly diagnosed sexually transmitted infection (STI) in the UK. Because approximately 70–80% of infections in women and up to 50% in men cause no symptoms, partners are frequently unaware they have been exposed. Without notification and testing, infected partners continue to carry and transmit the infection unknowingly, and the person who was originally treated faces a high risk of reinfection.
Partner notification also helps prevent the serious long-term complications of untreated chlamydia, including pelvic inflammatory disease (PID), tubal factor infertility, epididymo-orchitis, and reactive arthritis. Notifying partners is therefore not only an individual health concern but a public health responsibility.
Reinfection risk: If you are treated but your partner is not, you can be reinfected as soon as you resume sexual contact. Both partners must complete treatment and abstain from sex—or use condoms consistently—until treatment is finished and a minimum of seven days have passed.
Who Needs to Be Told?
The BASHH 2025 guidelines recommend notifying all sexual partners within a defined lookback period. Who counts as a partner depends on the type of sexual contact involved. In practice, this includes:
- Any person you have had vaginal, anal, or oral sex with during the relevant lookback period
- Partners with whom there has been direct genital contact, even without penetration
- Regular partners, casual partners, and one-off contacts alike—risk does not depend on relationship type
- Partners of all genders and sexual orientations: chlamydia affects everyone equally
- Any partner who may have had contact with your genitals, anus, or throat depending on the site of your infection
If you are in a long-term relationship, it is important not to assume your partner is uninfected simply because the relationship is monogamous. Chlamydia can persist silently for months or years, and the timing of acquisition may be unclear.
The Lookback Period Explained
The lookback period is the window of time during which sexual partners are considered at potential risk and should be notified. BASHH 2025 recommends the following lookback periods for Chlamydia trachomatis:
| Clinical Situation | Recommended Lookback Period | Notes |
|---|---|---|
| Symptomatic infection | All partners since symptom onset, or 6 months — whichever is longer | Symptom onset may predate diagnosis by weeks or months |
| Asymptomatic infection (no symptoms) | All partners in the past 6 months | If no partners in 6 months, notify the most recent partner regardless of date |
| No partners in past 6 months | Most recent partner notified, however long ago | The most recent partner is the most likely source and most at risk |
| Rectal or pharyngeal infection | Same 6-month lookback applies | Consider partners involved in the specific sexual practices associated with the infection site |
The six-month lookback period reflects the fact that chlamydia can persist silently for many months without symptoms. Identifying and treating partners from this wider window significantly reduces ongoing transmission within sexual networks.
How to Tell a Partner
There is no single “right way” to tell a partner. The method that feels most appropriate will depend on the nature of the relationship, your personal circumstances, and your comfort level. The most important thing is that the message is communicated clearly, without delay, and in a way that encourages the partner to get tested.
Patient Referral (You Tell Them Directly)
In most cases, BASHH guidelines recommend patient referral as the preferred first approach—meaning you contact the partner yourself. This can be done in person, by telephone, text message, or email. Direct communication is often more effective because it allows for questions and provides reassurance. When telling a partner:
1
Choose your timing and setting
Pick a moment when both of you are calm and not under pressure. A private, unhurried conversation reduces the chance of a defensive or distressed response. If you are worried about your safety, consider alternative notification methods.
2
Be direct and factual
Keep the message simple: “I’ve been told I have chlamydia and you may have been exposed. I wanted to let you know so you can get tested.” Avoid blame—it is impossible to know who acquired the infection first, and framing it as a health matter rather than a personal failing makes the conversation easier for both parties.
3
Explain that treatment is simple
Reassure the partner that chlamydia is fully treatable with a short course of antibiotics and that testing is straightforward—often just a urine sample or self-taken swab. Early treatment prevents complications.
4
Suggest where to test
Partners can test at a local GUM (genitourinary medicine) or sexual health clinic, via their GP, or using a home test kit. Many NHS sexual health services offer free postal test kits. Online pharmacies registered with the GPhC can also provide discreet home testing options.
5
Advise on abstinence until treatment is complete
Both partners should avoid sexual contact (or use condoms consistently) until at least 7 days after completing treatment and until any symptoms have resolved. This prevents reinfection before the antibiotic has fully cleared the infection.
Written or Electronic Notification
If a face-to-face or telephone conversation is not possible, a text message or email is entirely acceptable. The goal is to ensure the partner receives the information; the medium is less important than the act of notification. Several NHS sexual health services support a free anonymous notification service called SH:24 Tell Your Partner, which allows you to send an anonymous text or email to a partner via a third-party platform without revealing your identity.
Anonymous Notification Options
If you are unable or unwilling to contact a partner directly—for example, if the relationship has ended, you feel unsafe, or the partner is a casual contact whose details you have—anonymous notification is a valid and supported alternative.
GUM Clinic Health Adviser
Sexual health clinics employ specialist health advisers trained in partner notification. With your consent, they can contact partners on your behalf—without revealing who provided the information.
Anonymous Text / Email Services
Free online tools such as SH:24 Tell Your Partner or Inspot.org allow you to send an untraceable notification to a partner’s phone or email address without identifying yourself.
Contact Slips
Some GUM clinics provide printed contact slips that you can pass to a partner. The slip states that the holder may have been exposed to an STI and should attend for testing, without naming the referring person or the specific infection.
Provider Referral
If you provide your partner’s contact details to the clinic, a health adviser can make direct contact on your behalf (provider referral). This is particularly useful when you have lost contact with a partner or when safety is a concern.
Confidentiality: Any information you share with a sexual health clinic or health adviser about your partners is strictly confidential. Clinic staff will not contact a partner without your consent, and they will not disclose your identity to a partner unless you explicitly ask them to.
Already diagnosed? Start treatment today
Access Doctor is a GPhC-registered pharmacy (#9011198). If you have tested positive for chlamydia, our pharmacist independent prescribers can assess you online and issue a prescription for doxycycline (first-line) or azithromycin—with discreet next-day delivery.
Get Chlamydia Treatment OnlineWhat if a Partner Refuses to Test or Be Treated?
You cannot compel another person to get tested or treated for an STI. In the UK, there is no legal obligation on an individual to disclose an STI diagnosis to a partner, and equally there is no mechanism to force a partner to seek care. However, the ethical and public health case for notification is strong, and health advisers at sexual health clinics are experienced in navigating these situations.
If a partner refuses to test, consider the following options:
- Ask a sexual health clinic health adviser to contact the partner directly (provider referral)—hearing from a healthcare professional rather than an ex-partner can sometimes make a difference
- Send an anonymous notification by text or email so the partner at least has the information, even if they choose not to act on it immediately
- Use condoms consistently until you know the partner’s status, to protect yourself from reinfection
- Retest yourself at three months post-treatment if you have resumed sexual contact with an untreated partner
- Consider whether the relationship continues to pose a risk to your sexual health going forward
Expedited Partner Therapy (EPT): In some countries, clinicians can prescribe treatment for the untested partner directly (“patient-delivered partner therapy”). This is not currently standard practice in the UK NHS, primarily for clinical and regulatory reasons. Partners should be encouraged to attend a clinic or access their own GP or online service for assessment and treatment.
What Partners Should Do
A partner who has been notified of a potential chlamydia exposure should take the following steps as promptly as possible:
Full treatment guides: Doxycycline for chlamydia → · Azithromycin for chlamydia →
- Get tested: Attend a sexual health clinic, GP surgery, or order a home test kit. Testing is usually a simple urine sample (for men) or self-taken vaginal swab (for women), and results are typically available within a few days
- Avoid sexual contact or use condoms consistently until your test result is known and any treatment has been completed
- If the test is positive: Complete the full course of antibiotic treatment—doxycycline 100mg twice daily for 7 days is first-line per BASHH 2025—and notify any of your own partners from the preceding six months
- If the test is negative but you had recent sexual contact with the notified person: Consider retesting after 14 days to allow for the two-week window period, particularly if exposure occurred very recently
- Attend a sexual health clinic if you have symptoms, are pregnant, or have concerns about other STIs, as a broader screen may be appropriate
Protecting Yourself from Reinfection
Reinfection with chlamydia after treatment is common and significantly increases the risk of complications, particularly PID and tubal infertility in women. The most important protective steps are:
Complete Your Treatment Course
Take every dose of doxycycline as prescribed. Do not stop early even if you feel well. Incomplete treatment may not clear the infection fully.
Abstain for 7 Days After Treatment
Avoid penetrative sex (or use condoms) for at least 7 days after completing a 7-day course, or for 7 days after a single-dose treatment (azithromycin). Both you and any partner must have completed treatment.
Retest at 3 Months
BASHH recommends routine retesting at 3 months post-treatment for all patients, regardless of whether partners have been treated. Reinfection rates are highest in the first three months.
Use Condoms Consistently
Condoms reduce the risk of chlamydia transmission by approximately 50–90% when used correctly and consistently. They also protect against other STIs including gonorrhoea and HIV.
Retesting reminder: A test of cure (TOC) is not routinely recommended after standard doxycycline or azithromycin treatment in non-pregnant patients. However, retesting at three months post-treatment is recommended to detect reinfection—not to confirm that the original infection has cleared. Pregnant patients require a test of cure at 5–6 weeks post-treatment due to higher reinfection risk and foetal implications.
Getting Treatment for Chlamydia
For both the index patient and their notified partners, prompt treatment with the appropriate antibiotic is essential. Treatment options in the UK follow BASHH 2025 guidelines:
| Treatment | Regimen | When Used |
|---|---|---|
| Doxycycline (first-line) | 100mg twice daily for 7 days | Standard urogenital, rectal, or pharyngeal chlamydia in non-pregnant adults |
| Azithromycin (second-line) | 1g single dose | When doxycycline is contraindicated or not tolerated (not recommended for rectal infection) |
| Erythromycin (pregnancy) | 500mg four times daily for 14 days | Alternative in pregnancy when azithromycin is not suitable; under specialist guidance |
| Amoxicillin (pregnancy) | 500mg three times daily for 7 days | Alternative in pregnancy; test of cure mandatory |
Doxycycline is absolutely contraindicated in pregnancy. Pregnant patients must be referred to obstetric or GUM services for appropriate antibiotic selection and mandatory test of cure. For detailed information, see our guide to chlamydia in pregnancy.
First-line treatment
Doxycycline 100mg
BASHH 2025 first-line antibiotic for chlamydia. 100mg twice daily for 7 days. Suitable for urogenital and rectal infection.
View treatment →Second-line treatment
Azithromycin 1g
Single-dose second-line option when doxycycline is not suitable. Not recommended for rectal chlamydia.
View treatment →Confidential chlamydia treatment — online, next day
Access Doctor is a GPhC-registered pharmacy (#9011198). Our pharmacist independent prescribers issue prescriptions following a clinical assessment. Discreet packaging, next-day delivery across the UK.
Start Your Online AssessmentFrequently Asked Questions about Chlamydia Partner Notification
Do I have to tell my partner I have chlamydia?
There is no legal requirement in the UK to disclose a chlamydia diagnosis to a sexual partner. However, BASHH 2025 guidelines strongly recommend notifying all partners within the past six months on clinical and public health grounds. Untold partners remain at risk of complications from untreated infection, and you face a high risk of reinfection if they are not treated. If you are unwilling or unable to tell a partner directly, anonymous notification services are available through GUM clinics and online platforms.
How far back do I need to contact partners?
The standard lookback period is six months. If you had symptoms, you should notify all partners from the point your symptoms began, even if that is longer than six months ago. If you had no symptoms and no partners in the past six months, you should notify your most recent partner regardless of how long ago that was.
Can I tell a partner anonymously?
Yes. Several free services allow anonymous notification. You can use the SH:24 Tell Your Partner tool to send an anonymous text or email. Alternatively, a health adviser at a GUM clinic can contact partners on your behalf without revealing your name. Printed contact slips are also available from some clinics.
My partner says they tested negative — do I still need to use condoms?
It depends on timing. Chlamydia tests have a window period of approximately two weeks, meaning a test taken very soon after exposure may give a false-negative result. If your partner tested within 14 days of their most recent exposure with you, a repeat test at two weeks is advisable. If the negative result was obtained after the window period and you have both completed treatment, you can resume unprotected sex safely.
What if I have lost contact with a partner?
Do your best to reach the partner through any contact details you have, including social media. If you have no way of contacting them directly, inform the health adviser at your sexual health clinic. In some cases, provider referral is possible if you have the partner’s contact details. If all options are exhausted, document your efforts—you are not obligated to go to unreasonable lengths.
Can my partner get treatment without being tested?
In theory, epidemiological treatment (treating without testing) is sometimes offered at GUM clinics when a partner has had a confirmed exposure and testing is logistically difficult. However, standard practice in the UK is to test and then treat. Your partner should attend a sexual health clinic, GP, or use an online service to get assessed properly. This ensures the correct diagnosis, screens for other STIs, and allows for appropriate follow-up.
When can I have sex again after treatment?
You and your partner should avoid penetrative sex (or use condoms throughout) until both of you have completed the full course of treatment and at least 7 days have passed since the last dose. For a 7-day course of doxycycline, this means abstaining for the 7 days of treatment plus 7 days post-completion. For a single-dose azithromycin, abstain for 7 days after the dose. Both conditions must be met by both partners simultaneously.
Do I need to tell partners from before I think I was infected?
No. The lookback period works backwards from your diagnosis, not your estimated infection date. You should contact partners in the 6 months before diagnosis (or since symptoms began), not partners from years ago. Chlamydia does not persist indefinitely; in most cases it is acquired from a partner within the relevant lookback window.
Will the clinic contact my partner without telling me?
No. Sexual health clinics always seek your consent before contacting a partner on your behalf. All information shared with clinic staff is confidential and protected by data protection law. Staff will not contact anyone without your permission, and they will not reveal your identity to a partner unless you explicitly consent to this.
References
- British Association for Sexual Health and HIV (BASHH). UK National Guideline for the Management of Infection with Chlamydia trachomatis. 2025. www.bashh.org/guidelines
- Public Health England / UKHSA. Partner Notification for Sexually Transmitted Infections: A Resource for Health Advisers and Clinicians. www.gov.uk
- NHS. Chlamydia — Diagnosis and Treatment. www.nhs.uk/conditions/chlamydia/
- NICE CKS. Chlamydia — uncomplicated genital. Last revised 2024. cks.nice.org.uk
- Estcourt CS, et al. “Partner notification for sexually transmitted infections including HIV: systematic review.” Sex Transm Infect. 2020;96(5):341–350.
- SH:24. Tell Your Partner — Anonymous STI Notification Tool. sh24.org.uk/tell-your-partner
- British Medical Association. Confidentiality and Disclosure of Health Information. 2023. www.bma.org.uk
- Hosenfeld CB, et al. “Repeat infection with Chlamydia and gonorrhea among females: a systematic review of the literature.” Sex Transm Dis. 2009;36(8):478–489.
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting or stopping any treatment. Chlamydia treatment requires a clinical assessment; doxycycline and azithromycin are prescription-only medicines (POMs) available following assessment by a prescriber. In a medical emergency, call 999.