How to Claim a Council Tax Discount on an Annexe in England

Where to Apply

All annexe discounts and exemptions are claimed from your local billing authority — the council that sends your council tax bill. The Valuation Office Agency deals only with banding, not with discounts.

Most English councils offer an online portal, a downloadable PDF form, or an email address for annexe discount applications. Some still accept paper forms by post. The exact submission route varies by council, but the statutory requirements are the same across England.

Identify the Right Relief First

Before filling in any form, work out which relief applies to your situation:

Class W exemption (100% off) — the annexe is the sole or main residence of a dependent relative of a person living in the other dwelling; the relative is aged 65+, severely mentally impaired, or substantially and permanently disabled.

50% family annexe reduction — the annexe is used as part of the main home, or occupied by a relative (of any age, no dependency requirement).

Class T exemption (100% off) — the annexe is unoccupied and a planning condition prevents it from being let separately.

Single person discount (25% off, stackable) — only one countable adult lives in the annexe. This stacks with the 50% reduction for a combined 62.5% saving.

Getting the right category matters because each one requires different evidence and is assessed under different regulations.

What Evidence to Gather

For Class W claims, prepare:

• Proof of the relative's age (passport, birth certificate, or driving licence) if claiming under the age route
• A medical certificate from a registered practitioner if claiming under the severe mental impairment route
• Benefit award letters (Attendance Allowance, PIP, DLA) to support a disability or SMI claim
• A declaration of the family relationship
• Evidence the relative lives in the annexe as their sole or main residence — electoral register entry, utility bills, GP registration address

For Class T claims, prepare:

• A copy of the planning decision notice showing the ancillary-use condition
• Or a copy of the Section 106 agreement preventing separate letting

For the 50% family reduction, prepare:

• Evidence of the family relationship
• A declaration that the annexe is either used as part of the main home or occupied by a relative

For the single person discount, complete the council's standard SPD application confirming you are the only countable adult living in the annexe.

How to Submit

Contact your council's revenues department. Most councils list annexe discounts under "Council Tax discounts and exemptions" on their website. If there is no specific annexe form, use the general discount application and specify the type of relief you are claiming.

Include all supporting documents with the initial application. Incomplete applications are the most common cause of delays — councils cannot process a Class W claim without medical evidence, or a Class T claim without a planning restriction document.

Keep a copy of everything you submit, including the date and any reference number. You will need these if the application is delayed or refused.

Processing Timeline

Most councils aim to process applications within 21 to 28 working days. During this period, you remain legally obligated to pay your existing council tax bill. If the discount or exemption is granted, the council issues a revised demand notice and either credits your account or refunds the overpayment.

If the council asks for additional information, respond promptly — incomplete correspondence can restart the clock.

If the Application Is Refused

You have the right to request a formal internal review under Section 16 of the Local Government Finance Act 1992. The council then has two months to reconsider. If they reject the review or fail to respond within two months, you can appeal to the Valuation Tribunal for England — an independent body that hears the case for free.

Our Annexe Discounts and Exemptions Guide includes evidence checklists for each claim type, a template letter for Section 16 reviews, and the full step-by-step appeals process.

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