Cornwall Council Tax Severe Mental Impairment Exemption — How SMI Discount Works

The Severe Mental Impairment (SMI) disregard is one of the most valuable council tax reliefs in Cornwall — and one of the least claimed. A person with SMI is completely disregarded for council tax purposes, which can mean a 25% discount, a full exemption, or a significant boost to Council Tax Support entitlement.

What Severe Mental Impairment Means for Council Tax

Under Schedule 1 of the Local Government Finance Act 1992, a person qualifies as severely mentally impaired if:

1. A medical practitioner certifies that the person has a severe impairment of intelligence and social functioning (however caused) that appears to be permanent
2. The person receives a qualifying benefit. Cornwall Council lists a range; examples include:
   • PIP standard or enhanced daily living component
   • DLA care component (middle or higher rate)
   • Attendance Allowance
   • Employment and Support Allowance
   • Universal Credit with a Limited Capability for Work (LCW) or Limited Capability for Work and Work-Related Activity (LCWRA) element
   • Severe Disablement Allowance

Both conditions must be met. A dementia diagnosis alone isn't enough without the qualifying benefit, and receiving PIP alone isn't enough without the GP or consultant certificate.

What the SMI Disregard Does

A person with SMI is treated as if they don't live in the property for council tax purposes. The practical effects:

If the SMI person is the only resident: The property qualifies for a Class U exemption — zero council tax.

If the SMI person lives with one other liable adult: That other adult becomes the sole liable person and qualifies for the 25% single person discount.

If the SMI person lives with a partner who claims CTS: The SMI disregard reduces the household's council tax liability (through the single person discount), and the remaining bill is then assessed for Council Tax Support. Additionally, the SMI person's disability benefits trigger higher premiums in the CTS calculation.

The medical certificate and qualifying-benefit evidence are both needed. Getting the paperwork in promptly matters; if eligibility began earlier, include evidence of when both conditions were met and ask Cornwall Council to assess the start date.

How to Apply in Cornwall

The SMI disregard is not part of the Council Tax Support application. It's a separate council tax discount that you claim through Cornwall Council's revenues team:

1. Get a medical certificate. Ask the person's GP or hospital consultant to certify in writing that they have a severe impairment of intelligence and social functioning that appears permanent. There's no standard NHS form — a letter on headed paper is enough.
2. Confirm the qualifying benefit. Gather the most recent award letter for PIP, DLA, Attendance Allowance, ESA, or UC with LCW or LCWRA. Cornwall accepts other qualifying benefits too.
3. Contact Cornwall Council revenues (0300 1234 171) or apply through the online portal. Submit the medical certificate and benefit evidence.

Ask Cornwall Council to confirm the effective date. If the person has been certified and receiving a qualifying benefit for some time, provide evidence of those dates and ask whether the discount can be backdated.

Common Conditions That Qualify

SMI covers a range of conditions that cause permanent impairment of intelligence and social functioning:

• Dementia (Alzheimer's, vascular, Lewy body, frontotemporal)
• Severe learning disabilities
• Severe brain injury (from stroke, accident, or illness)
• Advanced Parkinson's disease with cognitive impairment
• Huntington's disease

The key word is "permanent." Temporary conditions or conditions expected to improve don't qualify.

Combining SMI With Council Tax Support

If you're the carer or partner of someone with SMI and you claim Council Tax Support, the SMI disregard works in your favour twice: it reduces the base council tax liability (potentially triggering the single person discount), and the person's disability benefits boost your CTS Applicable Amount through disability premiums.

The Cornwall Council Tax Reduction guide explains how SMI interacts with the CTS calculation and includes an award audit worksheet to verify both discounts are correctly applied.

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