How the council tax bills are worked out

Every calculator on the site calls one engine, a set of pure functions fed by two files: the council figures, generated by a script from the official spreadsheets, and a parameter file holding the national rules for 2026/27 (1 April 2026 to 31 March 2027). No amount is typed into a page. Both files were last checked against their sources on 19 October 2026.

1. The Band D figure of each council

England: 296 billing authorities, from Table 9 and Table 10 of MHCLG, Council Tax levels set by local authorities in England 2026 to 2027 (25 March 2026). Table 9 gives the "area council tax for a dwelling occupied by two adults", parish precepts averaged across the council; Table 10 splits the Band D figure between the billing authority, its parishes, the county council or the Greater London Authority, the police and crime commissioner, the fire authority and, where one sets a precept, the combined authority. Last year's figure comes from the 2025 to 2026 edition of Table 9. Wales: 22 councils, from Welsh Government, Council tax levels: April 2026 to March 2027, with the county, community council and police elements. Scotland: 32 councils, from the Council Tax by band table of Scottish Government, Council tax datasets: Council Tax by band 2026-27, which excludes water and sewerage.

The script that turns the spreadsheets into data, scripts/data/build-councils.py, checks that Table 9's Band D equals the sum of Table 10's parts for every English council, and that it finds exactly 296, 22 and 32 councils. It can be run again on next year's files.

2. From Band D to your band

A band is a fixed share of Band D, set in section 5 of the Local Government Finance Act 1992 (Local Government Finance Act 1992, section 5 (band proportions)). England: A 6/9, B 7/9, C 8/9, D 9/9, E 11/9, F 13/9, G 15/9, H 18/9. Wales: A 6/9, B 7/9, C 8/9, D 9/9, E 11/9, F 13/9, G 15/9, H 18/9, I 21/9. Scotland since 1 April 2017 (bands E to H raised by 7.5 %, 12.5 %, 17.5 % and 22.5 %): A 240/360, B 280/360, C 320/360, D 360/360, E 473/360, F 585/360, G 705/360, H 882/360 (Council Tax (Substitution of Proportion) (Scotland) Order 2016). The charge is rounded to the penny, as councils print it. For all 296 English councils the eight charges computed this way match Table 9 to within a penny, and the tests check it on every build.

3. Who lives there

The bill assumes two adults. If only one adult counts, it is reduced by 25 %; if nobody counts, by 50 % (Local Government Finance Act 1992, section 11 (discounts)). People who do not count, the "disregarded", are listed in Schedule 1 of the 1992 Act: full-time students and student nurses, apprentices and young people on funded training, under-18s, 18 and 19 year olds at school or college, live-in carers, the severely mentally impaired, diplomats and some others (Local Government Finance Act 1992, Schedule 1 (persons disregarded for discount), GOV.UK, Council Tax: who has to pay, discounts for people who are disregarded). A home where everyone is a full-time student is exempt, not discounted (Council Tax (Exempt Dwellings) Order 1992, GOV.UK, Council Tax discounts for full-time students). The calculator asks how many adults count; it does not test each person against the schedule for you.

4. Disabled Band Reduction

A home adapted for a disabled resident is charged at the band below (Council Tax (Reductions for Disabilities) Regulations 1992, GOV.UK, Council Tax discounts for disabled people). In Band A the charge falls to five sixths of Band A, which is 5/9 of Band D in England and Wales and 200/360 in Scotland: in Highland the Band A council tax drops from £1,089.33 to £907.77, the figure the Highland Council publishes. The reduction is applied before any discount, as on a real bill.

5. Second homes and empty homes

England: from 1 April 2025 a council may charge up to 100 % more on a furnished home that is nobody's main residence; on a home empty and substantially unfurnished for 1 year or more (since 1 April 2024), up to 100 %, then 200 % after 5 years and 300 % after 10 years (Local Government Finance Act 1992, section 11B (higher amount for long-term empty dwellings, England), MHCLG, Guidance on the council tax premiums on long-term empty homes and second homes (1 November 2024), GOV.UK, Council Tax: second homes and empty properties). Wales: up to 300 % on both since 1 April 2023, after one year for an empty home (Welsh Government, Council tax premiums for long-term empty and second homes: guidance). Scotland: since 1 April 2026 the national default is 100 %, and each council may set a higher or lower rate, or none (Scottish Government, Local government finance circular 6/2026: second and long-term empty homes (25 March 2026)). The national tables do not say which council charges what, so the calculator starts from the legal maximum in England, 100 % in Wales and the national default in Scotland, and lets you type your council's rate. Exceptions such as a home for sale, probate or job-related accommodation are not modelled.

6. Scottish Water

Every Scottish bill also collects Scottish Water's charges, the same in every council area: for 2026/27 the Band D water charge is £301.95 and the waste water charge £350.37, up 8.67 % (Scottish Water, Your charges 2026-2027). They use their own ratios (240, 280, 320, 360, 440, 520, 600, 720 over 360), so Bands E to H are lighter than for council tax. The single person discount and the Disabled Band Reduction apply to them too; a premium does not. Checked against Highland Council, Council Tax and Scottish Water charges 2026 to 2027: Band A for two adults £1,524.21, for one adult £1,143.16 (the council prints £1,143.15, a penny of rounding), and with the reduction £1,270.17.

7. Instalments

Unless you ask otherwise, the bill is paid in 10 monthly instalments; in England and Wales you have the right to ask for 12 (Council Tax (Administration and Enforcement) Regulations 1992, Schedule 1 (instalments), GOV.UK, Council Tax: paying your bill). Every instalment except the first is the total divided by the number of instalments, rounded to the nearest pound, and the first takes what is left. A Band B home in Birmingham at £1,837.81 is paid as £181.81 then nine of £184.00. We apply the same arithmetic to Scotland, where councils set their own schedules. Part of a year is charged by the day, the annual bill divided by 365.

8. Tests

Among the cases checked on every build: every English band charge against Table 9; Highland's 2026 to 2027 table for Band A (two adults, one adult, Disabled Band Reduction) with water and waste water; the Scottish ratio of Band H; Band I in Wales at 21/9; the England premium caps at 1, 5 and 10 years; the instalment rounding of the 1992 regulations. A failing test stops the build.

9. What the calculator does not do

• Council Tax Reduction for people on a low income, which each council runs with its own scheme in England (see GOV.UK, Council Tax Reduction);
• the exact parish or community council of your address: we use the average of the council area, so a bill in a parish with a high precept can be a few tens of pounds higher;
• local discounts a council may grant, such as for care leavers, and the exceptions to premiums;
• special expenses charged in part of a district, and Northern Ireland, which has domestic rates instead of council tax.

Method version: 2026-10-19. A figure that looks wrong: contact.