The Money Saving Expert founder appeared on Good Morning Britain on ITV, saying the discount is “massively under-publicised”.
He said: “It’s the one people don’t talk about. It’s the severe mental impairment discount for council tax.
“If somebody has a lack of social functioning, severe dementia will do it, severe Parkinsons, or have had a severe stroke, for typical examples, then as well as that they’re eligible for certain benefits, they can be disregarded for council tax.”
The ‘severely mentally impaired’ (SMI) Council Tax discount is a reduction off of a household’s Council Tax bill, worth, at a minimum, 25%, all the way up to, in some cases, no charge at all being due.
It applies in England, Scotland and Wales.
‘What can you do if your council tax is going up?’ – @susannareid100@MartinSLewis explains what you can do, as he points out that many people could be missing out on discounts. pic.twitter.com/VkucbcAS2K
— Good Morning Britain (@GMB) April 1, 2025
The SMI Council Tax discount size depends on who you live with
Most Council Tax discounts are based on how many qualifying adults live in a household. Having SMI means you don’t count towards this, much like full-time students or under-18s
- SMI living alone: household gets 100% discount (ie, you pay nowt)
- SMI living with an adult carer: household gets 50% discount
- SMI living with one qualifying adult: household gets single-person reduction, so 25% discount
- SMI living with two or more qualifying adults: household pays full Council Tax, so no discount (because the household is paying for those adults, not for you)
A household where someone with an SMI lives with an under-18 or a full-time student still gets the 100% discount. See Martin Lewis’ full Council Tax discounts help guide.
How to claim Council Tax SMI discounts
What you need to do in order to claim the discount differs depending whether you are in England and Scotland or in Wales.
In England and Scotland you will need to get a claim form from your council, a doctor’s diagnosis and some supporting evidence to accompany the form.
While in Wales you can print the application form from the Welsh Government website before getting a doctor’s diagnosis and sending your form to your local council tax office.
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SMI is a medical diagnosis in itself, but the underlying cause could be a condition such as profound learning difficulties, multiple sclerosis, dementia (including Alzheimer’s), the result of a severe stroke or something else.
When your claim is accepted, the discount should be applied automatically each year, meaning you will not need to reapply.
You may also be eligible for benefits – contact the DWP to apply for these.
