Most inpatients aren't detained, and that should stay the default where it's lawful.
What is an informal patient?
An informal patient is in hospital for mental disorder without being detained under the Act. Section 131 makes clear that nothing in the Act stops someone being admitted this way, or staying on after a section ends.
Voluntary admission is the everyday name for it. Where someone can be treated safely and lawfully without detention, they shouldn't be detained (Code chapter 1). When a person with capacity agrees to come in, informal admission is usually right (Code 14.14).
Who can be admitted informally?
Usually someone with capacity who agrees. That isn't an absolute rule, especially where there's a clear risk to them or others (Code 14.15). Consider detention if their mental state and past experience strongly suggest they'll change their mind, with a resulting risk (Code 14.16).
Consent must be real. Never use the threat of detention to get agreement; it's likely to make any apparent consent invalid (Code 14.17).
Informal admission when someone lacks capacity
The can allow treatment for mental disorder in someone's best interests when they lack capacity (Code 13.31). But the Code says someone who lacks capacity to consent to admission, and is likely to be deprived of liberty, should never be admitted informally, content or not. Use the Act or, for an adult, (Code 13.4, 13.53).
That rule was written around Cheshire West, which [2026] UKSC 16 overruled on 2 June 2026. Confinement is now judged on many factors. Someone who lacks capacity may still give valid consent, if they're aware of their situation and can say they're content with it.
Where there's serious doubt, consent can't be inferred (AGNI). DHSC says to keep using DoLS or the court where there's any doubt about valid consent, or the restrictions are significant. So check your trust's current policy, and remember that compliance isn't consent. More on DoLS after AGNI and MHA or MCA?
Can an informal patient leave?
Yes. Informal patients must be allowed to leave if they wish, unless they're going to be detained under the Act. Tell them, and their carer or advocate where appropriate, and explain any ward rules about moving around (Code 4.51).
If you think they need detaining and it isn't safe to wait:
- Section 5(2). The doctor or approved clinician in charge of their treatment, or their nominated deputy, can hold them for up to 72 hours while an assessment is arranged.
- Section 5(4). A mental health or learning disability nurse can hold an inpatient already being treated for mental disorder for up to 6 hours. It ends sooner if a doctor or clinician who can use s5(2) arrives (Code 18.22, 18.25).
These powers hold someone; they don't admit them. Don't admit someone informally just so you can use them (Code 18.8). Informal patients should be told the holding powers exist (Code 26.46). More on holding powers.
Locked doors and restrictions
A locked ward door doesn't by itself make an informal patient detained, but depending on how it's run it can amount to a deprivation of liberty (Code 8.10). It's unlikely to be a deprivation of liberty if a patient with capacity knows the policy and agrees to stay on that basis (Code 8.11). They should know who to ask, and they must be able to leave when they want.
Warning signs include stopping an informal patient leaving, telling them they'll be detained if they don't do as staff ask, and keeping them in conditions amounting to seclusion (Code 26.51). Seclusion is for detained patients only. If an informal patient needs it as a last resort, assess for detention straight away (Code 26.106).
Treatment for informal patients
's power to treat without consent doesn't apply (s56). Treatment needs their consent, or the MCA if they lack capacity for that decision. A patient with capacity can refuse any treatment.
Two parts of Part 4 apply to everyone. Section 57 treatments, such as surgery to destroy brain tissue, need consent and a second opinion. Section 58A, which covers , applies to every patient under 18 (s56(1), (5), Code 24.29).
If they refuse treatment you think is essential, consider whether they now meet the criteria for detention. Don't use the threat of it as leverage (Code 14.17).
Informal patient rights
- To leave whenever they want, unless they're held under s5 or an application is made (Code 4.51, 8.11).
- To know where they stand. The Act imposes no duty, but they should have their legal position and rights explained, including how to complain and the consent rules (Code 4.49, 4.50).
- No tribunal, and no nearest relative discharge power. Those come with detention.
- An IMHA only if s57 treatment, or for under-18s s58A treatment, is being considered (s130C(3), Code 6.10). The 2025 Act will extend IMHAs to informal inpatients in England, but that isn't in force (2025 Act s40).
- Human rights in private hospitals. Since 6 April 2026, a private provider treating an NHS-funded inpatient for mental disorder is bound by the Human Rights Act, detained or not (s142C).
Informal admission at 16 and 17
A 16 or 17-year-old with capacity decides. If they agree, they can be admitted even if a parent objects. If they refuse, a parent can't consent for them (s131(3), (4), Code 19.53).
A parent can't consent for them either if they can't decide but don't lack capacity under the MCA, for example because they find the decision too hard (Code 19.54). If they do lack capacity, the MCA may allow informal admission, unless it amounts to a deprivation of liberty (Code 19.57). A parent can't consent to that (Re D [2019] UKSC 42).
If informal routes fail, consider the Act. If it doesn't apply, take legal advice about the court (Code 19.55, 19.57). The ward must suit their age (s131A). More on children and young people.
Informal vs detained patients
| Informal patient | Detained patient (s2 or s3) | |
|---|---|---|
| Legal basis | Their consent, or the MCA if they lack capacity | An application under the Act |
| Leaving hospital | Free to leave, unless held under s5(2) or s5(4) | Only with s17 leave from the |
| Treatment for mental disorder | Consent, or the MCA | Can be given without consent under s63, with s58 safeguards after three months |
| Tribunal | No | Yes |
| Nearest relative | Can still require an assessment (s13(4)), but has no discharge power | Informed (s2) or consulted (s3), and can order discharge |
| IMHA | Only for s57, or s58A if under 18 | Yes |
| Section 117 aftercare | Not from informal admission | Yes after s3, not after s2 |
A worked example
At 2am, an informal patient with severe depression tells the nurse she's leaving to end her life. The duty doctor is in A&E and can't come for an hour.
The nurse can use s5(4), because she's being treated for mental disorder as an inpatient and needs to be stopped from leaving immediately. That holds her for up to 6 hours, or until the doctor arrives. If the doctor then makes a s5(2) report, the 72 hours run from when the nurse's record was made (s5(5)). Arrange the assessment for s2 or s3 straight away (Code 18.19).
The rules in brief
- Consent. Informal admission usually means a person who has capacity to consent to it and agrees. It isn't barred for someone who lacks capacity, unless the arrangements would deprive them of liberty.
- Lacks capacity. Don't admit informally if they lack capacity to consent and the arrangements would deprive them of liberty. Use the or DoLS, or at 16 or 17 the MHA or the Court of Protection, because DoLS starts at 18.
- Wanting to leave. Informal patients are free to leave. If you think they need detaining, the holding powers are s5(2) and s5(4).
- Treatment. Part 4's power to treat without consent doesn't apply. Treatment needs their consent, or the MCA if they lack capacity. Section 57, and s58A for under-18s, still apply.
- At 16 or 17. A young person with capacity decides: a parent can't override their consent or refusal (s131).
Read more: MHA 1983, s131 · MHA Code of Practice 2015, chapter 13: Mental capacity and deprivation of liberty
Questions trainees ask
Can an informal patient leave?
Yes. If you think they need detaining and it isn't safe to wait, the holding powers are s5(2) for the doctor and s5(4) for the nurse.
Can you admit someone informally if they lack capacity?
Only if the arrangements won't deprive them of liberty. If they would, use the or, for an adult, . At 16 or 17 it's the MHA or a court order.
What is an informal patient?
Someone in hospital for mental disorder who isn't detained under the Mental Health Act. Informal patients are free to leave unless they're held under a holding power.
Is voluntary admission the same as informal admission?
Yes, in practice. Voluntary is the everyday word, and the Mental Health Act's term is informal admission, under s131.
Can an informal patient refuse treatment?
Yes, if they have capacity. The Act's power to treat without consent doesn't apply to them, though the special rules for s57 treatments, and for in under-18s, still do.
Can parents admit a 16 or 17-year-old informally?
Not against their wishes if they have capacity. A capable 16 or 17-year-old decides for themselves, and a parent can't override a refusal (s131).
Do informal patients have the right to a tribunal or an advocate?
There's no tribunal, because they aren't detained. An is available only if s57 treatment, or ECT for an under-18, is being considered.
Test yourself
Quick-fire
A 16-year-old with capacity refuses informal admission. A parent can override that:
Show the answer
No