Do people with dementia have to pay council tax?

Often not in full. Someone medically certified as severely mentally impaired (SMI) who is entitled to a qualifying benefit such as Attendance Allowance is disregarded for council tax. Living alone, that means a 100% exemption; living with one other adult, that adult gets a 25% discount.

What counts as severe mental impairment for council tax?

A severe impairment of intelligence and social functioning that appears permanent, certified by a doctor. Dementia qualifies clinically, and the GP's certificate is free. The certificate alone is not enough — a qualifying benefit such as Attendance Allowance must also be in payment or in place.

Which benefits qualify for the SMI council tax discount?

Attendance Allowance, the daily living component of PIP, and the middle or higher rate of the DLA care component all qualify. The person must be entitled to one of them as well as being medically certified — both conditions are needed.

Can the SMI council tax discount be backdated?

Often, yes. Many councils backdate the discount to the date both conditions were first met — the medical impairment and the qualifying benefit — which can be years and can mean a substantial refund. Councils vary in how generous they are, so always ask about backdating when you apply.

How do you apply for the SMI discount?

Through your parent's local council. You request its SMI form, ask the GP to sign the medical certificate (this is free), and return the form with proof of the qualifying benefit, such as the Attendance Allowance award letter. The council then applies the discount or exemption to the bill.

What if my parent doesn't get Attendance Allowance yet?

Claim it first. Entitlement to a qualifying benefit is one of the two SMI conditions, so the council tax discount usually cannot start without it. Dementia claims are won on supervision and prompting needs, and once the award is in place the SMI application can follow — with backdating to when both conditions were met.

Council tax discount for dementia (SMI): how to claim

Someone with dementia who receives a qualifying benefit such as Attendance Allowance can be “disregarded” for council tax — which means a 100% exemption if they live alone, or a 25% discount if they live with one other adult. The claim is a short council form plus a free GP certificate, it is widely under-claimed, and many councils will backdate it to when the conditions were first met — sometimes worth years of refunded council tax.

If your parent has recently been diagnosed, this is step three on the admin list in our dementia diagnosis roadmap — after Power of Attorney and benefits, and before almost everything else, because it is quick and the savings recur every year.

This guide is general information, not financial or legal advice. For advice about your own situation, speak to a regulated professional, or a free service such as Citizens Advice or Age UK.

What is the SMI council tax disregard?

Council tax assumes two adults live in each home; a single adult gets 25% off. The rules also say some people are “disregarded” — counted as if they were not there. Full-time students are the best-known example. Less well-known: someone who is severely mentally impaired (SMI) is disregarded too.

“Severe mental impairment” is the legal wording, not a judgement — it is defined as a severe impairment of intelligence and social functioning that appears to be permanent. Dementia qualifies clinically, and doctors sign these certificates for dementia routinely. The disregard applies in England, Scotland and Wales (Northern Ireland uses a rates system with its own reliefs).

Because nobody sends families a letter about it, the discount is widely under-claimed. Councils apply it readily when asked — the problem is that most people never ask.

Who qualifies for the dementia council tax discount?

Two conditions, and both must be met:

A doctor certifies the person as severely mentally impaired. For dementia this is usually straightforward: the GP signs a short medical certificate that comes with the council’s form, and signing it is free.
The person is entitled to a qualifying benefit. The main ones are Attendance Allowance, the daily living component of PIP, and the middle or higher rate of the DLA care component.

Note the word entitled. The benefit condition is about entitlement, and it is the reason claiming Attendance Allowance comes first in the admin order: without a qualifying benefit, the SMI discount usually cannot start, however clear the diagnosis.

How much is the SMI discount worth?

It depends on who else lives in the household:

Household	Effect on the bill
Your parent lives alone	100% exemption — no council tax at all
Your parent lives with one other adult (spouse, or you)	That adult is treated as living alone: 25% discount
Your parent lives with two or more other adults	Usually no reduction — but other discounts or council tax support may still apply

For a parent living alone, the bill simply stops. For a couple where one partner has dementia, the household gets the same 25% off as a single occupant. Either way it is worth hundreds of pounds a year for many households — and unlike a benefit, it is not means-tested and needs no renewal once granted.

How do you claim, step by step?

Check the qualifying benefit is in place. If your parent already gets Attendance Allowance, PIP daily living or DLA care (middle or higher), you are ready. If not, see below.
Get the council’s SMI form. Search the council’s website for “severe mental impairment council tax”, or phone the council tax team. Every council has its own form, but they all follow the same pattern.
Ask the GP to sign the medical certificate. The form includes a section for a doctor to certify the impairment. It is free — GPs should not charge for this one.
Send the form back with proof of the benefit — the Attendance Allowance or PIP award letter is ideal.
Ask about backdating — explicitly, in writing. More on this below, because it is where the real money often is.

The council will confirm the disregard and adjust the bill. There is no interview and no means test.

Can the discount be backdated?

Often, yes — and sometimes a long way. The disregard legally applies from when both conditions were met: the impairment existed and the qualifying benefit was in place. Many councils will backdate to that date, which for a parent who has had Attendance Allowance for several years can mean a refund covering all of them.

Practice varies, though. Some councils backdate generously as a matter of course; others ask for evidence of when the conditions were first met, and a few are stricter. So always ask, put the earliest date you can evidence in the application, and include anything that supports it — the benefit award letter shows when the benefit started, and the GP can often indicate when the impairment dates from.

What if the qualifying benefit isn’t in place yet?

Claim it first — for a parent over State Pension age, that means Attendance Allowance. Dementia claims succeed on supervision and prompting needs: reminders to take medication, encouragement to eat and wash, someone keeping an eye out for safety. Our guide to Attendance Allowance for dementia covers exactly what to write on the form, and the complete Attendance Allowance guide covers the rules and rates.

The sequencing matters but costs nothing: once the benefit is awarded, apply for the SMI discount and ask for backdating to when both conditions were met. A successful Attendance Allowance claim is itself usually backdated to the date the claim started, which helps.

Is there a discount for a live-in carer too?

Sometimes. Council tax rules also disregard certain live-in carers — a person living in the property to provide substantial care can be counted out of the household in some circumstances, which can create or preserve a discount. The conditions are specific (they exclude spouses caring for each other, among other things) and vary in the detail, so if someone has moved in to care for your parent, ask the council tax team whether the carer disregard applies as well. The two disregards can stack: a parent with SMI plus a disregarded live-in carer can take a household to a 50% discount.

What should you do next?

If your parent has dementia and a qualifying benefit, this is one of the quickest wins in the whole care-admin pile: one form, one free GP signature, and a bill that shrinks or disappears — possibly with a refund attached. If the benefit is not in place yet, start there.

And to see the full picture — Attendance Allowance, Pension Credit, council tax support and what they unlock together — run our free benefits check. It takes a few minutes and covers the lot in one pass.