How is the Band I bill in Carmarthenshire calculated?

The Band D rate published by Carmarthenshire for 2026/27 is £2,351 inclusive of every precept on the bill (billing authority, county or upper-tier in two-tier areas, police, fire, and parish where applicable). Band I is fixed at 21/9 of Band D under the Local Government Finance Act 1992, so the Band I annual bill is £2,351 multiplied by 2.333 which gives £5,486 before any discounts.

Can I get the 25% Single Person Discount?

Yes, if you are the only adult living at the property as your sole or main residence. The discount cuts the gross bill by 25%, so a Band I household in Carmarthenshire would pay £4,114 per year instead of £5,486. You have to apply to Carmarthenshire for it. If you get a discount by mistake you must tell the council, which can ask you to pay it back and charge a penalty: section 14 and Schedule 3 of the Local Government Finance Act 1992 provide for civil penalties.

What if everyone in the property is a full-time student?

An all-student household is 100% exempt from Council Tax, so the annual bill drops to £0. To count as full-time the course must last at least 1 year and involve at least 21 hours of study a week; for a course up to A level taken by someone under 20, at least 3 months and 12 hours a week. If a student lives with one non-student adult, the non-student gets the 25% Single Person Discount instead of full exemption.

Can I pay over 12 months instead of 10?

The bill is usually split into 10 monthly payments, and you can ask Carmarthenshire to spread it over 12 instead. For Band I the 10-instalment figure is £549 a month and the 12-instalment figure is £457 a month, before any discounts. The annual total is unchanged. If you are struggling to pay, contact the council straight away rather than missing an instalment.

Council Tax Band I in Carmarthenshire: 2026/27 Annual Bill

A Band I property in Carmarthenshire (Wales) pays £5,486 per year in Council Tax before any discount, based on the 2026/27 Band D rate of £2,351 inclusive of all precepts. Band I is fixed at 21/9 of Band D (233.3% of the local Band D rate) by statute, so the multiplier is the same in every billing authority in Wales.

Annual bill

£5,486

Before any discount

Monthly (10 instalments)

£549

April to January, default schedule

Monthly (12 instalments)

£457

Available on request

Discount scenarios for Band I in Carmarthenshire

How the £5,486 gross bill changes under the most common UK Council Tax reliefs. The disabled banded-down figure applies under the Disabled Band Reduction Scheme when the property has been adapted for a disabled occupant - the bill is charged as if the property were one band lower.

Scenario	Annual bill	Monthly (10)	Saving vs gross
Gross bill (2+ adults, no discount)	£5,486	£549	£0
After 25% Single Person Discount	£4,114	£411	£1,371
Disabled Band Reduction (banded down)	£4,702	£470	£784
100% all-student exemption	£0	£0	£5,486

Need a different scenario (severely mentally impaired disregard, Council Tax Reduction, or a mixed-adult household)? The main Council Tax calculator lets you model any combination.

Band I compared with nearby authorities

Same band, four closest Welsh authorities by Band D rate. Useful when comparing offers across council boundaries (the same band can vary by hundreds of pounds depending on the billing authority and its precepts).

Local authority	Band D (LA)	Band I annual	Difference vs Carmarthenshire
Carmarthenshire (this page)	£2,351	£5,486	-
Flintshire	£2,376	£5,544	+£58
Wrexham	£2,309	£5,388	-£98
Rhondda Cynon Taf	£2,289	£5,341	-£145
Swansea	£2,238	£5,222	-£264

All bands in Carmarthenshire

Statutory band ratios applied to Carmarthenshire's published 2026/27 Band D rate of £2,351. If your property is on a different band than I, jump straight to the right row below.

Band	Ratio	Annual	Monthly (10)	Monthly (12)
Band A	6/9	£1,567	£157	£131
Band B	7/9	£1,829	£183	£152
Band C	8/9	£2,090	£209	£174
Band D	9/9	£2,351	£235	£196
Band E	11/9	£2,873	£287	£239
Band F	13/9	£3,396	£340	£283
Band G	15/9	£3,918	£392	£327
Band H	18/9	£4,702	£470	£392
Band I (this page)	21/9	£5,486	£549	£457

How Carmarthenshire sets the Band D rate

Council Tax is a property tax administered by your billing authority. Carmarthenshire's published Band D figure for 2026/27 (£2,351) is the sum of every precept that appears on a resident's bill: the billing authority's own charge, the police and crime commissioner precept, fire and rescue, and any parish or town council precept that applies. Every band is a fixed statutory proportion of Band D. England and Wales set these in ninths: Band A is 6/9 of Band D, Band B is 7/9, Band C is 8/9, Band D is 9/9, Band E is 11/9, Band F is 13/9, Band G is 15/9, Band H is 18/9, and Band I in Wales is 21/9.

The valuation date is 1 April 2003 (Wales rebanded in 2003 and added Band I for the most valuable properties). New builds are slotted into a band by analogy with comparable older stock. The Valuation Office Agency (VOA) handles banding decisions and band challenges.

The 2026/27 published Band D figures are typically confirmed by individual billing authorities in February or March, before the billing year starts on 1 April. This page uses the latest confirmed published rate (2026/27) so the underlying provenance is auditable.

The English council tax referendum limits do not apply in Wales: the referendum rules in Chapter 4ZA of the Local Government Finance Act 1992 cover only authorities in England (s.52ZA, checked 2026-10-20). In Wales the Welsh Ministers have a different power: if they consider an authority's budget requirement for the year excessive, judged against principles they determine, they may designate or nominate the authority (Local Government Finance Act 1992 s.52B, checked 2026-10-20).

Cite or embed - free under CC BY 4.0

Full Council Tax calculator - change LA, band, household, and discounts.
Band I across the UK - top 20 authorities at Band I.
LTT (Wales) - Land Transaction Tax on property purchase.
Mortgage affordability - factor Council Tax into housing cost.

Frequently asked questions

How is the Band I bill in Carmarthenshire calculated?: The Band D rate published by Carmarthenshire for 2026/27 is £2,351 inclusive of every precept on the bill (billing authority, county or upper-tier in two-tier areas, police, fire, and parish where applicable). Band I is fixed at 21/9 of Band D under the Local Government Finance Act 1992, so the Band I annual bill is £2,351 multiplied by 2.333 which gives £5,486 before any discounts.
Can I get the 25% Single Person Discount?: Yes, if you are the only adult living at the property as your sole or main residence. The discount cuts the gross bill by 25%, so a Band I household in Carmarthenshire would pay £4,114 per year instead of £5,486. You have to apply to Carmarthenshire for it. If you get a discount by mistake you must tell the council, which can ask you to pay it back and charge a penalty: section 14 and Schedule 3 of the Local Government Finance Act 1992 provide for civil penalties.
What if everyone in the property is a full-time student?: An all-student household is 100% exempt from Council Tax, so the annual bill drops to £0. To count as full-time the course must last at least 1 year and involve at least 21 hours of study a week; for a course up to A level taken by someone under 20, at least 3 months and 12 hours a week. If a student lives with one non-student adult, the non-student gets the 25% Single Person Discount instead of full exemption.
Can I pay over 12 months instead of 10?: The bill is usually split into 10 monthly payments, and you can ask Carmarthenshire to spread it over 12 instead. For Band I the 10-instalment figure is £549 a month and the 12-instalment figure is £457 a month, before any discounts. The annual total is unchanged. If you are struggling to pay, contact the council straight away rather than missing an instalment.