Section 2 vs Section 3 of the Mental Health Act: A Care Staff Guide

When people talk about being sectioned, they are often talking about section 2 or section 3 of the Mental Health Act 1983. These are the two main civil routes into hospital detention, and they work differently. Care and healthcare staff meet patients under both, and need to understand what each means for the person's rights and the plan for their care. This guide sets out the key differences.

It is general information, not legal advice. Check the current Code of Practice, and note that the Mental Health Act 2025 will change some rules over time. See our overview of the Mental Health Act 2025 changes.

Section 2: admission for assessment

Section 2 is a detention for assessment, or for assessment followed by treatment. It lasts up to 28 days. It cannot be renewed as a section 2, although a patient can be moved onto section 3 during that period if more time is needed.

An approved mental health professional, usually shortened to AMHP, normally makes the application. The nearest relative can theoretically apply but this is rare. Two doctors provide medical recommendations, and one of them must be approved under section 12 of the Act as having special expertise in mental disorder. The doctors' examinations must not be more than five clear days apart, and the patient must reach hospital within 14 days of the last examination.

Two conditions must be met. The person has a mental disorder of a nature or degree that warrants detention in hospital for assessment, and detention is necessary for their health or safety or to protect other people.

Section 3: admission for treatment

Section 3 is the longer-term detention route. It lasts up to six months in the first instance. It can be renewed for a further six months, and after that for periods of 12 months at a time.

The criteria are stricter and more specific. According to the Act, the patient must meet all of the following:

• they have a mental disorder of a nature or degree that makes it appropriate for them to receive medical treatment in hospital
• it is necessary for their health or safety, or for the protection of other people, that they receive such treatment
• the treatment cannot be provided unless they are detained
• appropriate medical treatment is available for them

Again, an AMHP normally applies on the basis of two medical recommendations. A key difference from section 2 is that the AMHP must consult the nearest relative before applying unless this is not practicable, and the application cannot go ahead if the nearest relative objects. Our guide to the nearest relative and nominated person explains this role and how it is changing.

Tribunal rights

Patients on both sections can apply to the Mental Health Tribunal, but the timing is different.

• Section 2. A patient can apply only in the first 14 days.
• Section 3. A patient can apply in the first six months, once in each following six-month period, and then once a year.

The tribunal must discharge a patient if it is not satisfied that they meet the criteria. For more detail, see our guide to mental health tribunal rights.

Side by side

• Purpose. Section 2 is for assessment. Section 3 is for treatment.
• Length. Section 2 lasts up to 28 days with no renewal. Section 3 lasts up to six months and can be renewed.
• Nearest relative. For section 3 the AMHP must consult them where practicable, and their objection stops the application. For section 2 the AMHP must take reasonable steps to inform them, but their objection does not stop it.
• Tribunal. Section 2 allows an application in the first 14 days. Section 3 allows applications over a longer timetable.
• Treatment. After three months of detention, medication for mental disorder needs consent or a second opinion certificate. This applies across both.

Who can discharge a patient?

A patient can be discharged by the tribunal, by the hospital managers or by the responsible clinician. In some circumstances the nearest relative can also make an order for discharge, subject to the clinician's right to bar it if the patient would be dangerous.

What staff should do

• Know which section applies. Check the section and the expiry date on admission paperwork and on every handover.
• Explain rights. Make sure the patient has been told, in a way they understand, about their section, their rights and how to apply to the tribunal.
• Prompt advocacy. Patients under both sections are likely to be entitled to an independent mental health advocate.
• Watch the dates. Section 2 ends after 28 days unless the patient is moved to section 3 or becomes informal.
• Record clearly. Note the patient's views, any request to appeal and what you told them.

Common mistakes

• Letting a section 2 run out without a plan.
• Describing both sections as the same thing.
• Not telling patients about their right to a tribunal within the first 14 days of section 2.
• Forgetting that rights and consent rules change over time, especially after three months.

Frequently asked questions

Can section 2 be extended?

No. It cannot be renewed as a section 2, but a patient may be moved onto section 3.

Who decides someone should be detained?

An AMHP makes the application, on the basis of two medical recommendations, one from a section 12 approved doctor.

Can a patient be detained without a hospital bed?

Detention under these sections is in hospital. Other routes, such as community treatment orders and guardianship, apply in the community.

Where can teams find training?

See the CPD hub for professional development options for care and healthcare teams.

Learnsignal will update this guide as reforms take effect.