Back to Care Funding (NI)
Council care & support

Council Tax Severe Mental Impairment (SMI) Disregard

A council tax discount for households where someone has been medically certified as severely mentally impaired — typically dementia, severe learning disability or stroke. Often unclaimed; can mean 25–100% off the bill.

Official linksLast verified 27 April 2026

Who it helps

Households where one person has been medically certified with a severe and permanent mental impairment (dementia, severe learning disability, severe stroke effects, advanced Parkinson's, Huntington's, etc.) AND receives a qualifying disability benefit. The certifier must be a registered medical practitioner — usually the GP.

The full picture

The Severe Mental Impairment (SMI) Disregard is a long-standing council tax rule that removes a person from the household count for council tax purposes when a doctor has certified them as severely mentally impaired. It's been in legislation since 1992 but is one of the most under-claimed council tax discounts — many families with dementia don't know it exists.

Who counts as "severely mentally impaired" for council tax purposes: - Diagnosed with a condition that severely impairs intellectual and social functioning, expected to be permanent - Common qualifying conditions: dementia (Alzheimer's, vascular, Lewy body, frontotemporal), severe learning disability, severe stroke effects, Parkinson's disease in advanced stages, Huntington's disease, severe and persistent depression with cognitive impact - Receives one of: Attendance Allowance, PIP daily living, DLA middle/highest care, ADP daily living, Constant Attendance Allowance, Severe Disablement Allowance, Incapacity Benefit, Income Support with disability premium, Universal Credit Limited Capability for Work

What the disregard means for the bill: - If the SMI person lives alone, the home is fully exempt from council tax (Class U exemption — 100% off) - If they live with one other adult, that adult gets the Single Person Discount (25% off) - If they live with two or more other adults, no discount applies but the SMI person doesn't count for council tax purposes - Backdating: many councils backdate to the date the qualifying benefit started — sometimes years of refunds

In England, Scotland and Wales the rule is the same. Northern Ireland has an equivalent under the Rates system: Disabled Persons Allowance + SMI exemption from rates.

Worth knowing before you apply

  • Often missed for dementia families — every English council has applicants but uptake is patchy
  • Backdating is often available to the date the qualifying disability benefit started — can be thousands of pounds
  • Stacks with other discounts (Single Person, Disability Reduction) — apply for all of them
  • Northern Ireland uses the Rates system: Disabled Persons Allowance + SMI exemption are the equivalent
  • The medical certificate is signed by a GP (usually free) — some councils have their own form, others accept any doctor's letter
  • A renewal isn't needed unless circumstances change — the disregard stays in place
  • If the SMI person lives alone, the property is exempt (Class U) — 100% off council tax
  • If the SMI person lives with one other adult, that adult gets the 25% Single Person Discount as if they lived alone

How to claim

Two parts to the application: 1. Get a doctor's certificate confirming severe mental impairment. The GP signs a council form (different councils use different templates) at no charge. 2. Provide proof of a qualifying benefit (AA, PIP, DLA, ADP, etc.) award letter. Then submit both to the council tax department of your local council. Decisions usually take 2–6 weeks. Backdated refunds often arrive within a further 2 weeks.

Disabled Persons Allowance / Lone Pensioner Allowance (LPS)

Independent advice

More help is out there

If your situation is complex, these UK-wide charities and government services can give free, independent advice.

Last verified 27 April 2026
← All Care Funding for NI