What is the test for capacity to engage in sexual relations?

Capacity to engage in sexual relations is one of the most sensitive and complex areas of Court of Protection law. It sits at the intersection of autonomy, safeguarding, human rights, and personal relationships.

The law recognises that decisions about sexual relationships are deeply personal. Unlike many other decisions under the Mental Capacity Act 2005, the Court of Protection cannot make a best interests decision about whether someone should have sex or who they should have sexual relations with.

This distinction is crucial and has significantly shaped the legal test for capacity in this area.

In a discussion between Court of Protection specialists Holly Miéville-Hawkins and Sophia Withers, the pair explored how the courts assess capacity to engage in sexual relations, why the threshold is intentionally lower than other capacity tests, and how the landmark Supreme Court decision in A Local Authority v JB [2021] UKSC 35 transformed the legal framework.

Why capacity to engage in sexual relations is treated differently

Under section 27 of the Mental Capacity Act 2005, certain decisions are excluded from the Court of Protection’s best interests jurisdiction.

These include:

• consenting to marriage
• consenting to sexual relations
• divorce
• adoption decisions

This means that even if a person lacks capacity to engage in sexual relations, the court cannot consent on their behalf.

That differs from many financial or welfare decisions.

For example:

The consequence of this legal position is significant.

Because only the individual themselves can consent to sexual relations, the courts have deliberately developed a lower and more generalised test for capacity in this area.

For individuals and families navigating these issues, understanding the wider framework of mental capacity and Court of Protection law is often essential.

The legal framework under the Mental Capacity Act

As with all capacity assessments, the starting point is sections 1 to 3 of the Mental Capacity Act 2005.

The court must assess whether the person can:

• understand information relevant to the decision
• retain that information
• use or weigh that information
• communicate their decision

Following the Supreme Court decision in A Local Authority v JB, the courts clarified the relevant information a person must understand when deciding whether they have capacity to engage in sexual relations.

What information must a person understand?

The current legal test requires a person to understand several core concepts relating to sexual relationships.

Key elements of the test

The inclusion of mutual consent was one of the most important developments arising from A Local Authority (Respondent) v JB.

The Supreme Court confirmed that capacity to engage in sexual relations is not solely about whether the individual understands their own consent. They must also understand that:

• the other person must consent
• consent can be withdrawn at any time

This represented a major evolution in the law and aligned the Mental Capacity Act framework more closely with modern principles of sexual autonomy and criminal law.

Capacity to engage in sexual relations is an active test

One of the most important legal distinctions in this area is that the test concerns capacity to engage in sexual relations, not simply the ability to consent to a one-off act.

That distinction matters.

The courts recognise that sexual relationships involve:

• ongoing interaction
• changing circumstances
• communication
• continuing consent

As discussed in the interview, this means the individual must be able to understand and assess consent on an ongoing basis.

In practice, this includes understanding:

• that consent is continuous
• that someone can change their mind
• that agreement once does not mean agreement forever
• that both parties must actively consent

This is why the test, while described as a “lower bar”, still contains multiple layers of understanding.

Why the threshold is deliberately lower

The courts have repeatedly stressed the importance of avoiding overly protective or paternalistic approaches.

Sexual relationships are considered a fundamental aspect of human identity and private life under Article 8 of the European Convention on Human Rights.

If the threshold for capacity were set too high, many vulnerable adults could effectively be denied the right to sexual expression altogether.

The courts therefore aim to strike a balance between:

• protecting vulnerable individuals from exploitation
• preserving personal autonomy and dignity

This balancing exercise is central to many health and welfare disputes within the Court of Protection, particularly where safeguarding concerns arise.

In more complex cases involving disputes over relationships, care restrictions, or safeguarding measures, advice relating to health and welfare authorisation may also become relevant.

What most people do not realise about this area of law

Many people assume that capacity assessments in sexual relationships are focused primarily on vulnerability or risk.

In reality, the legal test is intentionally issue-specific and relatively narrow.

The courts are not assessing whether:

• the relationship is wise
• the relationship is healthy
• family members approve
• professionals believe the person may be exploited

Instead, the focus is on whether the individual can understand the core relevant information required by law.

This distinction is often difficult for families and carers, particularly where there are understandable safeguarding concerns.

Common issues in sexual capacity cases

Cases involving capacity to engage in sexual relations frequently arise alongside broader safeguarding and welfare concerns.

Common scenarios include:

• adults with learning disabilities entering relationships
• concerns about coercive relationships
• online sexual relationships
• restrictions in supported living or care settings
• disputes between families and local authorities
• allegations of exploitation
• balancing safeguarding with autonomy

In some situations, there may also be overlap with concerns about financial exploitation or predatory relationships, particularly where intimate relationships involve dependency or influence. Specialist advice relating to financial abuse and predatory marriages may become important in those circumstances.

Common mistakes in capacity assessments

Professionals and families sometimes misunderstand the scope of the legal test.

Common mistakes include:

• confusing vulnerability with incapacity
• focusing too heavily on risk
• imposing moral judgments about relationships
• failing to distinguish between unwise decisions and incapacity
• overlooking the importance of mutual consent

The Mental Capacity Act makes clear that a person should not be treated as lacking capacity simply because they make a decision others consider unwise.

When professional advice is essential

Legal advice is often necessary where:

• there are disputes about a person’s sexual relationships
• safeguarding restrictions interfere with private life
• local authorities seek court intervention
• care providers impose supervision or restrictions
• capacity assessments are challenged
• criminal law concerns intersect with mental capacity issues

These cases are often emotionally charged and legally complex. They require careful balancing of:

• autonomy
• dignity
• safeguarding
• human rights
• proportionality

In contested matters, specialist litigation support and expert witness services may also assist in resolving disputes.

FAQ

What is the legal test for capacity to engage in sexual relations?

A person must be able to understand, retain, use and weigh information about sexual activity, consent, pregnancy, sexually transmitted infections, and the ability of either party to withdraw consent.

What case changed the law on sexual capacity?

The Supreme Court decision in A Local Authority v JB clarified that a person must understand the need for the other person to consent to sexual activity.

Can the Court of Protection decide who someone should have sex with?

No. Under section 27 of the Mental Capacity Act 2005, the court cannot make best interests decisions about sexual relations.

Is the test person-specific?

No. Unlike capacity for contact, capacity to engage in sexual relations is generally issue-specific rather than person-specific.

Why is the threshold considered lower?

Because sexual relationships are fundamental to personal autonomy and the court cannot consent on behalf of the individual.

Conclusion

Capacity to engage in sexual relations remains one of the most legally and ethically challenging areas of the Mental Capacity Act.

The courts continue to balance two competing principles:

• protecting vulnerable individuals from harm
• preserving the right to personal autonomy and intimate relationships

The Supreme Court’s decision in A Local Authority (Respondent) v JB reinforced that sexual relationships involve mutual and ongoing consent, while still maintaining a relatively accessible threshold for capacity.

For families, carers, professionals, and vulnerable individuals themselves, these cases require careful and specialist consideration. The legal test is nuanced, evolving, and deeply connected to fundamental human rights.