Best interests
It's their interests, seen from their side. Not a family vote, and not the team's preferred option.
What is a best interests decision?
Once someone lacks capacity for a decision, anything done for them must be in their best interests (s1(5)). The Act doesn't define best interests. Section 4 gives a process instead (Code 5.5). It only starts once you've assessed capacity for this decision.
In Aintree v James [2013] UKSC 67 the Supreme Court said the purpose of the test is to consider matters from the patient's point of view (para 45). That means their welfare in the widest sense: social and psychological, not just medical (para 39).
It isn't a substituted judgment test, but reliably known wishes can carry great weight. There are two exceptions to best interests: a valid and applicable advance decision, and research (Code 5.4).
The best interests checklist in section 4
The checklist is a minimum. Work through every item, even if only to say why it doesn't apply.
| What section 4 requires | In practice | |
|---|---|---|
| No assumptions | Not merely on age, appearance, condition or behaviour (s4(1)) | Watch for quiet assumptions, such as how much risk someone with a learning disability should be 'allowed' to take. |
| Regaining capacity | Consider whether, and when, they'll regain it (s4(3)) | If they're likely to and the decision can wait, don't decide now. |
| Participation | Permit and encourage them to take part, and improve their ability to (s4(4)) | Done well, this sometimes shows they can decide after all. |
| Wishes, feelings, beliefs and values | Past and present, especially anything written when they had capacity (s4(6)) | Behaviour counts too: pleasure, distress, lifelong habits. If you depart from a written statement, record why (Code 5.43). |
| Consultation | Anyone they named, carers, people interested in their welfare, and any attorney or deputy (s4(7)) | Skip consultation that was practicable and appropriate, and you can't rely on the section 5 defence. |
| Life-sustaining treatment | Not motivated by a desire to bring about their death (s4(5)) | There's a strong presumption in favour of prolonging life, but it can be displaced. |
Anyone other than the court complies if they follow these steps and reasonably believe the decision is in the person's best interests (s4(9)).
Who is the best interests decision-maker?
- Day-to-day care. The carer most directly involved at the time (Code 5.8).
- Treatment. The clinician responsible for it. In hospital, that's usually the consultant in charge, even when a team contributes.
- Attorney or deputy. They decide matters within their authority, and should be consulted on others (Code 5.55).
- The Court of Protection, when it's asked to decide.
Being next of kin gives no legal power to decide for an adult. Relatives are consulted, often closely, but without an LPA or deputyship they have no veto. In an organisation, one person should be accountable for the conclusion.
Aintree v James: what the Supreme Court said
Mr James was critically ill in intensive care. The question was whether invasive treatments, including CPR, would be in his best interests if he deteriorated.
- Ask the right question. Is it in their best interests to give the treatment? If not, withholding it is lawful (para 22).
- Futile means of no benefit, not 'unable to cure the underlying illness' (paras 40 and 43).
- Recovery means a quality of life they'd value, not a return to full health (paras 40 and 44).
- Their wishes are judged as theirs, not by what a reasonable patient would want (para 45).
- No demands. The court can't make a doctor give a treatment they won't offer. Nor can a patient with capacity (para 18).
Best interests meetings and disagreements
- Meetings aren't a legal requirement. They help with complex or serious decisions. A written account from a relative can work better than a crowded room.
- Minute it. Record what was shared and decided, and circulate a draft so people can check it.
- Agreement isn't the test. A consensus can still be wrong for the person. Responsibility stays with the decision-maker (Code 5.64).
- Weigh conflicting views by how long people have known the person and their relationship with them (Code 5.67).
- Escalate in steps: an advocate, a second opinion, a case conference, mediation, then the Court of Protection (Code 5.68).
- Not every decision is a best interests decision. What to offer, such as a funded care package, is the public body's call. Best interests chooses between the options actually available.
Writing it down: the balance sheet
List the realistic options. For each, set out the benefits and risks to the person, how likely each is, and how much it matters to them. One benefit can outweigh many risks if it matters enough.
Then write a separate conclusion: which option, why, and why nothing less restrictive would do. Record who you consulted, and why you left anyone out (Code 5.15, 5.51). The balance sheet supports your judgement. It doesn't replace it.
The rules in brief
- Don't decide on age, appearance, condition or behaviour alone.
- Think about timing. Could they regain capacity? Could the decision wait?
- Involve them as far as you can.
- Their past and present wishes, feelings, beliefs and values count, especially anything written down.
- Consult anyone named by them, carers, anyone interested in their welfare, and any attorney or deputy.
- Life-sustaining treatment. The decision mustn't be motivated in any way by a wish to bring about their death.
Read more: MCA 2005, s4 · MCA Code of Practice 2007, chapter 5: Best interests · 39 Essex guidance note - best interests (May 2025) (commentary)
Acting without consent: sections 5 and 6
The everyday legal cover for care and treatment of someone who lacks capacity.
What does section 5 of the Mental Capacity Act do?
Section 5 is a defence, not a power. Take reasonable steps to establish whether someone lacks capacity, and reasonably believe they do and that the act is in their best interests. You're then protected as if they'd consented (s5(1)-(2)).
It covers everyday care and treatment: washing, feeding, giving medication, taking blood, taking someone to hospital (Code 6.5). You need no formal authority for these. You do need that reasonable belief, and to be able to explain it.
It doesn't excuse negligence (s5(3)), and it can't override a valid advance decision (s5(4)).
Restraint under section 6: necessary and proportionate
Restraint means using or threatening force to make someone do something they resist, or restricting their movement whether they resist or not (s6(4)). Two extra conditions apply.
- Necessary. You reasonably believe it's needed to prevent harm to them (s6(2)). You need objective reasons. Never restrain just to make a task easier (Code 6.44).
- Proportionate. To how likely and how serious the harm is (s6(3)): the least intrusive type, the minimum force, the shortest time (Code 6.47).
- Less restrictive first. Consider alternatives, and ask others involved what works (Code 6.48).
The Code's example: holding someone's arm as they cross a busy road can be proportionate. Stopping them going outdoors at all wouldn't be (Code 6.47).
What sections 5 and 6 can't cover
- Harm to others. That's not the test. The common law allows necessary action to prevent harm to others, and the may apply (Code 6.43).
- A deprivation of liberty. That needs DoLS, a Court of Protection order, or s4B while a court decision is sought.
- A valid decision by an attorney or deputy within their authority (s6(6)). You can still give life-sustaining treatment, or prevent a serious deterioration, while the court decides (s6(7)).
- Part 4 treatment. Treatment for mental disorder regulated by of the MHA goes under the MHA, not the MCA (s28).
- A capacitous refusal. If they can decide, they decide.
Section 5, common law or the MHA? A quick guide
| Usually covered by | Watch for | |
|---|---|---|
| Washing or feeding someone who lacks capacity | s5, in their best interests | If they resist, s6 applies |
| Re-siting a drip for a delirious patient | ss5 and 6 | Brief, proportionate and recorded |
| Stopping a confused patient walking into traffic | s6, to prevent harm to them | Minimum force, shortest time |
| Stopping a patient hitting someone else | Common law, or the MHA | Not the MCA test |
| Keeping someone where they'd be deprived of liberty | , a court order or the MHA | Sections 5 and 6 don't authorise it |
| An antipsychotic for a patient on s3 | Part 4 of the MHA | Not the MCA (s28) |
When it's unclear which Act applies, work it through on MHA or MCA.
Restraint on the ward: practical points
Write down what you did, why, for how long, and what else you tried first. If restraint is becoming routine, review the care plan. That it's lawful doesn't make it right.
Watch for drift towards confinement. Regular restraint, sedation to manage behaviour, one-to-one care to stop someone leaving, and covert medication they'd object to all point towards a deprivation of liberty. Ask whether you now need authorisation.
On a psychiatric ward, the MHA Code's guidance on restrictive interventions may also apply. See restraint and use of force.
The rules in brief
- Section 5. If you've taken reasonable steps to assess capacity, and reasonably believe they lack it and that what you're doing is in their best interests, you're protected as if they'd consented. It doesn't cover negligence.
- Section 6, restraint. Using or threatening force, or restricting movement, is allowed only if you reasonably believe it's necessary to prevent harm to them. It must also be proportionate to how likely and how serious that harm is.
- Harm to others isn't the MCA test. That's common law or the MHA.
- Deprivation of liberty needs more than s5 and s6: DoLS, the court, or s4B while a court decision is sought, for life-sustaining treatment or a vital act.
Read more: MCA 2005, s5 · MCA 2005, s6 · MCA Code of Practice 2007, chapter 6: Protection for people providing care or treatment
Questions trainees ask
What must a best interests decision consider?
The person's past and present wishes, feelings, beliefs and values, whether they'll regain capacity, how far they can take part, and the views of carers and anyone they named. Never just their age, appearance, condition or behaviour.
When is restraint allowed under the MCA?
Only if you reasonably believe it's necessary to prevent harm to the person, and it's proportionate to how likely and serious that harm is.
Who makes a best interests decision?
Usually the person doing the act: the carer for daily care, or the clinician responsible for a treatment. An attorney or deputy decides matters within their authority, and the Court of Protection settles disputes.
Is a best interests meeting a legal requirement?
No. Nothing in the Act requires a meeting, but one can help with complex or serious decisions. If you hold one, keep a detailed record and circulate a draft.
Can a family member make a best interests decision?
Yes, for day-to-day care they give themselves (Code 5.8). For anything else, such as treatment, only as an attorney or deputy with authority for that decision. Otherwise they must be consulted and their views count, but they don't decide.
What did Aintree v James decide?
That best interests means looking at the person's welfare in the widest sense, from their point of view. The question is whether it's in their best interests to give a treatment, not whether to withhold it.
Does section 5 of the MCA authorise a deprivation of liberty?
No. Sections 5 and 6 cover care, treatment and proportionate restraint. A deprivation of liberty needs , a Court of Protection order or the .
Test yourself
A man with advanced dementia lacks capacity to decide where to live. Nobody holds an LPA or deputyship. His daughter wants a care home; his son wants him home with carers. How is it decided?
Show the answer
C. Best interests is about him, seen from his side. The decision-maker weighs his past and present wishes, feelings and values and consults the family. No relative has a veto without an LPA or deputyship.
A man with delirium lacks capacity and keeps pulling out the drip that's giving him antibiotics for sepsis. A nurse holds his arm while the line is re-sited. What makes this lawful?
Show the answer
B. Brief restraint is covered by ss5 and 6 if you reasonably believe it's needed to prevent harm to him and it's proportionate to that harm. If the restrictions grow into a deprivation of liberty, they need authorising.
Quick-fire
Restraint under the MCA must be needed to prevent harm to
Show the answer
The person