Lewisham Council Tax Severe Mental Impairment (SMI) Exemption

What the SMI Exemption Gives You

Severe Mental Impairment (SMI) relief is one of the most valuable council tax reductions available — and one of the most under-claimed. If you qualify, the effect depends on your household:

Living alone or with full-time students only: a Class U full exemption applies, meaning zero council tax.

Living with one non-disregarded adult: the person with SMI is disregarded for headcount purposes, so the remaining adult qualifies for the 25% single person discount.

Living with a partner who also has SMI: both are disregarded, and the property gets a full Class U exemption.

Living with other people who are all disregarded from council tax: Lewisham lists a 50% discount for this household situation, subject to its criteria.

This is a status-based reduction, not means-tested. Your income, savings, and employment don't matter. If council tax liability remains after SMI relief, the household can ask about Council Tax Reduction under the separate means-tested scheme.

Who Qualifies

Two conditions must both be met:

1. A medical certificate from a GP or consultant confirming the person has a severe impairment of intelligence and social functioning that appears to be permanent. The wording matters — it needs to say "severe mental impairment" or words to that effect. Conditions that commonly qualify include dementia, severe learning disabilities, severe brain injuries, and advanced Parkinson's disease.

2. The person receives a qualifying benefit. Examples include:

• PIP Daily Living component (either rate)
• Attendance Allowance
• DLA Care component (middle or higher rate)
• ESA with the support component
• Incapacity Benefit (long-term rate)

The benefit condition is separate from the medical certificate. If the person may qualify for a benefit but is not receiving one, ask Lewisham whether another qualifying benefit applies before relying on the SMI exemption.

How to Apply in Lewisham

The person liable for council tax should complete Lewisham's SMI application; a representative can complete it if the person with SMI is liable. You'll need:

• The medical certificate completed by a GP or hospital doctor
• Proof of the qualifying benefit — a PIP, AA, or DLA award letter, or ESA support group decision

Upload the documents with the application. If the person met the conditions earlier, ask Lewisham to assess whether it can apply the reduction retrospectively.

Backdating and Refunds

Unlike working-age CTR backdating, which is discretionary and generally limited by the local scheme to up to one month or up to six months where continuous good cause is proved, SMI relief can be applied retrospectively to an earlier qualifying period. If someone has had dementia and received Attendance Allowance for three years but never applied for SMI relief, ask the council to assess whether the reduction can be backdated for that period.

This makes it worth applying even if the person's condition was certified long ago. Gather the GP certificate, the benefit award history, and apply. The refund can be substantial — a full Class U exemption on a Band D property in Lewisham saves £2,237.33 per year.

SMI and Council Tax Reduction Together

If the household still has council tax liability after SMI relief, the household may be able to claim CTR on the remaining bill. SMI relief and CTR non-dependant deductions are separate rules; SMI status alone does not establish that a non-dependant deduction is waived. Check the CTR decision notice against the rules for your or your partner's qualifying benefits.

For help navigating both the SMI exemption and Lewisham's means-tested Council Tax Reduction scheme — including how the two interact with single person discount and disability band reductions — the Lewisham Council Tax Reduction guide walks through every relief and how they stack.

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