Council tax on a granny annexe

Council tax By Council Tax Helpline, 10 September 2026

In short

• A self-contained annexe is usually banded separately from the main home.
• An annexe lived in by a dependent relative is exempt: aged 65 or over, severely mentally impaired, or substantially and permanently disabled.
• An annexe used as part of the main home, or lived in by a relative, gets a 50% discount if it is not exempt.
• An empty annexe that cannot be let separately under planning rules is exempt.
• These are the rules in England. Wales and Scotland have their own versions.

Does a granny annexe pay council tax?

An annexe is a self-contained part of a property, such as a granny flat, a converted garage, or a garden annexe with its own kitchen and bathroom. It is usually given its own council tax band, separate from the main home.

Whether you pay, and how much, depends on who lives in it and how it is used.

When an annexe is exempt

In England, an annexe is exempt, with nothing to pay, if it is lived in by a dependent relative of someone living in the main home. A dependent relative is someone who is:

• Aged 65 or over, or
• Severely mentally impaired, or
• Substantially and permanently disabled

An empty annexe is also exempt if it cannot be let separately without breaching planning rules.

The 50% annexe discount

If the annexe is not exempt, it gets 50% off if:

• It is used by the household of the main home as part of that home, for example as a spare bedroom or study, or
• It is lived in by a relative of the people in the main home

If only one adult lives in the annexe

An annexe is treated as a separate home. If only one adult lives there, the single person discount may apply too. See single person discount.

Quick check

Could you be paying too much?

Tick anything that applies to your home.

• Only one adult lives in the home

  Single person discount: 25% off. How it works

• Someone is a full-time student, an apprentice, or under 18

  They are not counted. That can mean 25% off, or no bill at all if everyone is a student. How it works

• Someone has dementia, a severe learning disability or a similar condition, and gets a disability benefit

  Severe mental impairment: 25% off, 50% off, or no bill at all. It can be backdated for years. How it works

• Someone gives 35 hours or more of care a week to a person they live with

  The carer may not be counted, which can bring a discount. How it works

• A disabled person lives here and needs an extra room, a second bathroom or kitchen, or uses a wheelchair indoors

  Disabled band reduction: charged at one band lower. Not means-tested. How it works

• Your income is low, or you get Universal Credit, Pension Credit or another benefit

  Council Tax Reduction can cut the bill, and on Pension Credit it often covers all of it. How it works

• The home is empty because the person who lived there died, moved into care, or is in prison

  The home may be exempt: no council tax at all. How it works

• Someone aged 18 to 24 has left local authority care

  Care leavers are exempt in Wales and Scotland, and most councils in England exempt them too. How it works

Not sure what you are entitled to? We can check for you.

Ask us to check, free

How to claim

Ask your council for the exemption or discount, and explain who lives in the annexe and their relationship to the main household. Ask for it to be backdated if you have been paying the full amount when you should not have.

Wales and Scotland

Wales and Scotland have their own versions of these rules. Check with your council. If you are in Scotland, our sister service can help: