Council Tax Exemption for Dementia: The Severe Mental Impairment Disregard Explained

Thousands of families pay full council tax on a home where someone with dementia lives, without knowing that person could be disregarded from the bill. The severe mental impairment disregard is available in England and Scotland; Wales has a significant cognitive impairment exemption or discount. Northern Ireland uses domestic rates rather than Council Tax.

What the SMI Disregard Is

Under the Local Government Finance Act 1992 and the applicable Welsh rules, a person certified as having a severe mental impairment (called significant cognitive impairment in Wales) may be disregarded for Council Tax if the other eligibility conditions are met. The impairment must be severe and appear permanent; a dementia diagnosis alone does not establish eligibility.

The practical effect depends on who else lives in the property:

• Person with dementia lives alone: full council tax exemption (the bill drops to zero)
• Person with dementia lives with one other adult: 25% single-person discount (the person with dementia is disregarded, so it is as though one person lives there)
• Both adults qualify for SMI disregard (for example, both have dementia): full exemption in England where both are liable for the bill

Two Requirements You Must Meet

The SMI disregard has two conditions, and you need both:

1. A doctor's certificate A registered medical practitioner must certify that the person has a severe mental impairment. Your GP can provide this. Some councils accept a letter; others have their own form. The legal test is that the impairment appears permanent; a dementia diagnosis alone does not establish that.

2. Entitlement to a qualifying benefit The person must be entitled to a qualifying benefit. The most relevant ones for older people with dementia are:

• Attendance Allowance at either rate
• Pension Age Disability Payment (Scotland) at either rate
• Personal Independence Payment (if claimed before reaching State Pension age)
• Disability Living Allowance (if an existing award)
• Incapacity Benefit or Severe Disablement Allowance

This is where the order matters: if the person is not entitled to any qualifying benefit, check whether they can claim Attendance Allowance or PADP. Once the qualifying-benefit condition is met, use the award information when applying for the Council Tax disregard.

How to Apply

1. Get the qualifying benefit in place (Attendance Allowance or PADP)
2. Ask your GP to certify the severe mental impairment
3. Contact your local council's council tax department and ask for the SMI disregard application form
4. Submit the form with the medical certificate and proof of the qualifying benefit

Processing times vary by council, but the discount can usually be backdated to when both conditions were first met. Some councils backdate generously; ask specifically about this when you apply.

Common Mistakes to Avoid

Not applying at all. Councils do not automatically apply the SMI disregard. You have to ask for it.

Confusing SMI with the disabled band reduction. The disabled band reduction is a separate scheme that reduces your council tax band by one level if the property has been adapted for a disabled person (wider doorways, a ground-floor bathroom, extra space for a wheelchair). You can claim both the SMI disregard and the disabled band reduction if both apply.

Assuming the person needs to lack all capacity. The SMI disregard tests for severe impairment of intelligence and social functioning, not total incapacity. A person with moderate-to-advanced dementia who can still hold a conversation may still qualify if their social functioning is severely affected.

What It Could Save You

Council Tax varies by band and location. In 2026/27, the average Band D bill in England is £2,392 per year, so a full exemption saves that amount and a 25% discount saves £598. Combined with Attendance Allowance (up to £5,959 per year at the higher rate) and the Pension Credit Severe Disability Addition (£4,475 per year), the total household income increase can be substantial.

If you are putting together an Attendance Allowance or PADP claim for someone with dementia, our dementia claim guide covers the full process from describing care needs through to challenging a decision — and it flags the council tax SMI disregard as a next step once the benefit is awarded.

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