Health and care
The Mental Health Act 2025: what changes, and what is in force
The largest reform of the Mental Health Act 1983 in decades. It does not all arrive at once, and until a provision is commenced the 1983 Act continues to apply.
Checked against the published sources on 2 October 2026.
The short answer
The Mental Health Act 2025 received Royal Assent on 18 December 2025 and applies to England and Wales. Only a small number of provisions came into force early. Most of the changes that affect ward practice will be commenced in phases over several years, with a new statutory Code of Practice still to be produced.
- Royal Assent
- 18 December 2025
- Applies to
- England and Wales
- In force
- Only in part. Most changes are being phased in
- Until commenced
- The Mental Health Act 1983 continues to apply
The new test for detention
Under sections 2 and 3, a person can be detained only if there is a risk of serious harm to their own health or safety or to someone else's, considering the nature, degree and likelihood of that harm. For section 3 there must also be a real therapeutic benefit.
Who speaks for the person
The nominated person replaces the nearest relative. The person chooses their nominated person if they have capacity to do so, and the choice carries on if they later lose capacity. Independent advocacy is extended to informal patients on an opt-out basis, care and treatment plans become statutory, and services must help people make advance choice documents.
Shorter detention, earlier review
The initial period of detention under section 3 reduces from six months to three. A person detained under section 2 can apply to the tribunal within 21 days rather than 14.
Learning disability and autism
Once the relevant provisions commence, a person will no longer be able to be detained for treatment under section 3, or placed on a community treatment order, on the basis of a learning disability or autism alone.
This page explains what the rule says. It is not legal, regulatory, clinical or financial advice on your own position. Rules change, so read the sources listed beside it, and tell us at hello@wajd.co.uk if something here is out of date.
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Law and regulation updates for nurses · 1.5 CPD hours
The Mental Health Act 2025: what changes for nurses, and when
Questions people ask
Is the Mental Health Act 2025 in force?
Only in part. Most of the changes that affect ward practice will be commenced in phases over several years. Until a provision is commenced, the 1983 Act as it stands continues to apply.
Does it apply in Scotland and Northern Ireland?
No. It applies to England and Wales.
What replaces the nearest relative?
The nominated person, chosen by the patient where they have capacity to choose.
What should I follow at work today?
The Act as currently in force, the Code of Practice, your professional standards and your employer's policy. This page explains what the 2025 Act provides and is not a statement of what you may do in your role.