“Acid Test” no more

Crest of the UK Supreme Court

For more than a decade, the concept of deprivation of liberty has been heavily influenced by the 2014 Cheshire West Supreme Court judgment and its well-known "Acid Test":

• Is the person under continuous supervision and control?

• Is the person free to leave?

If the answer was "yes" to the first question and "no" to the second, the person was likely to be considered deprived of their liberty.

However, a new Supreme Court judgment published in June 2026 has fundamentally changed this position.

The court has overturned the Cheshire West approach and confirmed that deprivation of liberty should no longer be determined using the Acid Test alone. Instead, professionals must consider the person's overall circumstances, including their wishes, feelings, understanding of their situation and acceptance of their care arrangements.

This is one of the most significant developments in deprivation of liberty law since Cheshire West itself.

What does this mean for social care?

The judgment does not remove the need for safeguards or mean that deprivation of liberty no longer occurs. Many people living in care homes, supported living services, hospitals and other care settings may still be deprived of their liberty.

What has changed is the way this is assessed.

Managers and practitioners will need to develop a broader understanding of deprivation of liberty and move beyond a simple "Acid Test" approach. Greater emphasis is now likely to be placed on person-centred assessments, evidence of wishes and feelings, and the individual's experience of their care arrangements.

Why is training important?

Many staff and managers have been trained using the Cheshire West framework for over ten years. As guidance and practice begin to adapt to the new judgment, it will be important for organisations to ensure managers understand the changes and their potential implications for care planning, restrictions, best interests decision-making and deprivation of liberty processes.

The legal landscape has changed significantly, and keeping knowledge up to date will be essential for anyone with responsibilities for supporting people who may lack capacity to make decisions about their care and accommodation.

At RP Social Care Training, course materials are currently being reviewed to reflect this important legal development and its implications for adult social care practice.