Class T – Unoccupied annexe (restricted letting)

A Class T exemption applies to an unoccupied annexe (sometimes known as a “granny annex”, “studio annex”, or “self‑contained unit”) where a legal restriction prevents it being let separately from the main home.

This exemption recognises that some annexes are subject to planning restrictions or legal conditions that make them unsuitable for letting or separate occupation.

Because they cannot be lived in independently, they are exempt from Council Tax as long as they remain unoccupied.

An annexe is typically a self‑contained living space within or attached to a main property. It usually includes:

• a bedroom/living area
• bathroom facilities
• its own kitchen or kitchenette
• independent access, or semi‑independent access

For Council Tax purposes, an annexe is treated as a separate dwelling only if it is capable of being occupied independently and is recorded separately in the Council Tax valuation list.

A property qualifies for Class T when all of the following apply:

• The annexe is unoccupied, no-one must be living in the annexe
• No one is occupying the annexe in any form. Occupation by anyone – family, guests, tenants removes eligibility.
• The annexe is self‑contained and separately assessed for Council Tax
• It appears as a separate dwelling in the Council Tax valuation list.
• A legal restriction prevents it being let or occupied separately

The restriction is usually part of the planning conditions attached to the main property, such as:

• “This annexe may not be let as a separate dwelling”
• “Occupation allowed only in conjunction with the main house”
• “Annexe must remain ancillary to the main dwelling”

These conditions are common because annexes are often approved on the basis they will form part of the main household.

A Class T exemption cannot be awarded when:

• The annexe is occupied
• If a family member, friend, tenant, or anyone else lives in the annexe, the exemption ends.
• There is no planning restriction preventing separate occupation
• If the annexe could be legally let as an independent dwelling, even if the owner chooses not to let it, Class T does not apply.
• The annexe is used as occasional or short‑term accommodation

Examples that invalidate the exemption include:

• Using the annexe as a guest room
• Using the annexe for adult children occasionally
• Allowing a relative to stay temporarily
• The annexe is not separately banded for Council Tax

If it is not listed separately (i.e., part of the main dwelling), Class T does not apply. Instead, it is assessed as part of the main property.

For as long as:

• the annexe remains unoccupied, and
• it cannot legally be let separately.

There is no maximum time limit.

The exemption ends immediately if:

• someone moves into the annexe,
• the legal restriction is changed or removed by planning authorities, or
• the annexe becomes capable of being let separately.

If you want to apply for a Class T exemption or have a question

Use the Council Tax contact form and choose the following options:

• Under which service would you like to contact us? Select Council Tax
• What would you like to contact us about? Select Something else