Form

Council tax base (CTB): validation checks

Updated 28 September 2023

Applies to England

Introduction

1. On receipt of your form, a number of checks are carried out to confirm the form has been completed correctly. Where the data on the CTB(October 2023) form (referred to as the ‘current data’ throughout this note) varies significantly from that provided on last year’s CTB(October 2022) form (referred to as the ‘previous year’s figures’), or exceeds criteria set by the Department for Levelling Up, Housing and Communities (DLUHC), we seek an explanation for the variance. The department will always contact the named local authority contact to resolve an error or seek an explanation for all entries that fail our validation tests.

2. Explanation of changes are valuable to the Department, as they help us understand factors affecting the taxbase as well as reduces the risk that data has been entered in error. If validation explanations are inadequate, these will be queried back to the authority.

3. Examples of inadequate explanations are ‘OK’, ‘This is how it is’, ‘It’s changed’ or ‘Don’t know’. Examples of good explanations are ‘These figures are correct because x has occurred [which has caused y to happen]’ or ‘We don’t know exactly what has happened, but [x has occurred] which may be having an effect on [the number]’

Council tax bands

4. Please note that the validation checks, as mentioned below, will only be carried out for the total of each council tax band, not at individual band level. Please take care entering this data.

CTB form

5. Most validation checks and all calculations have been built into the CTB form. The CTB form provides space for local authorities to comment on any data that has failed the validation checks. Details of the checks incorporated in the CTB form are set out below.

General checks

Certification of the form

6. In addition to the excel version of the CTB form, an email from the CFO or Section 151 office confirming the form is correct is required. This should be sent to the Department for Levelling Up, Housing and Communities by Friday 13 October 2023. The statement required is shown both in the main form and in the guidance notes. We will not consider the form to be final until this statement is received, and this may result in the exclusion of the form.

Revised forms and alterations

7. If you need to make changes to the data you have already supplied, please submit a revised version of the form making it clear in the covering email that it is a revised form. We will still expect a copy of the revised spreadsheet version which must be signed and dated by the Chief Financial Officer (CFO).

Additional validation checks

8. As the “Title” page of the form states, there are 3 different coloured input cells in the CTB form:

• white background, black border
• white background, blue border
• green background, green border

White background, black border

9. These cells are blank for new data – please ensure all of these cells are completed.

10. When one of these cells has been completed there will be no error messages or formatting visible if the data appears to be valid. If, however, a value has been entered that is not possible (i.e. negative values for some cells), data entry will either be prevented, or the cell will change to red. If any red cells do appear, please amend any invalid data entry.

White background, blue border

11. This is known data entered by the Department for Levelling Up, Housing and Communities. Please check that you are content with the values – there should be no need to change any of this data.

12. The cells can be overwritten if you do wish to change an entry, however, please ensure that you follow any instructions that appear and give the reason for change in the Validation sheet.

Green background, green border

13. These cells are either calculations or are brought forward from other parts of the Excel workbook. The form is protected to prevent data entry in either the wrong cells or calculated cells. Please do not turn this protection off or attempt to enter data in these cells. Please check that you are happy with the calculations and contact us if you feel that one of these cells is returning an incorrect value.

General

14. Other validations are included in other parts of the form including the CTB (Supplementary) form. These validations are essential to prevent invalid or implausible values. If one of these occurs, a message will appear explaining the reason behind preventing or questioning the data entry. Please follow any instructions to ensure the correct data is entered in the form.

Arithmetic calculations

15. Before returning the form, please ensure that all arithmetic calculations are correct, and that data is specified to the correct number of decimal places. All arithmetic calculations have been built into the form. These cells have a green background with a green border and there should be no need to attempt to amend these cells. The calculations are as follows:

Part 1

Line 4: Number of chargeable dwellings on 2 October 2023

Line 4 = line 1 – line 2 – line 3

Line 6: Number of dwellings effectively subject to council tax for the band by virtue of disabled relief

Line 6 = line 5 moved to the next lower council tax band

Line 7: Number of chargeable dwellings adjusted in accordance with lines 5 and lines 6

Line 7 = line 4 – line 5 + line 6 (or in the case of column 1, line 6)

Line 15: Total number of dwellings in line 7 classed as empty on 2 October 2023

Line 15 = line 12 + line 13 + line 14

Line 18: Number of dwellings empty for more than 6 months after excluding properties empty due to flooding and those that previously would have received a class A exemption

Line 18 = Line 16 – line 16a – line 16b – line 17

Line 19: Number of dwellings in line 7 where there is a liability to pay 100% council tax before the Family Annexe discount is applied

Line 17 = line 7 – line 20

Line 20: Number of dwellings in line 7 that are assumed to be subject to a discount or a premium before the Family Annexe discount is applied

Line 20 = line 8 + line 9 + line 10 + flex empty row 95 (discount) + flex empty row 96 (premium)

Line 22: Number of dwelling equivalents after applying discounts (including the family annexe discount) and premiums to calculate the tax base

Line 22 (to 1 decimal place) = line 7 – (line 8 x 0.25) – (line 9 x 0.25) – (line 10 x 0.5) – flex empty row 88 (total reductions in dwelling equivalent after discounts & premiums are applied)

Line 24: Total number of band D equivalents

Line 24 (to 1 decimal place) = line 22 x line 23

Line 26: Tax base

Line 26 (to 1 decimal place) = line 24 column 10 + line 25

Part 2

Line 31: Total number of band D equivalents after allowance for council tax support

Line 31 (to 1 decimal place) = line 29 x line 30

Line 33: Tax base after allowance for council tax support

Line 33 (to 1 decimal place) = line 31 column 10 + line 32

Specific validation checks

Main form

Test 1: Total number of dwellings on the Valuation List

The figure from CTB Form Line 1 should be exactly the same as the data provided by the Valuation Office Agency as at 11 September 2023. Any revision concerning the list at 11 September 2023 supplied by the Listing Officer to the authority will have to be confirmed in writing by the Local Valuation Office. A check has been built into the validation sheet (Test 1 CTB (October 2023) form) to highlight changes in the total. Any differences shown on the validation sheet should be investigated immediately with your Local Valuation Office. Please provide a copy of the confirmation email from the local Valuation Office when submitting the form.

Test 2: Total number of dwellings year-on-year

We will require an explanation if the total number of dwellings in Line 1 has increased by more than 1,000 dwellings and more than 1.5% or has reduced by 0.5% on last year’s figures.

Test 3: Number of dwellings on valuation list exempt on 2 October 2023

We check both the change and percentage change in total number of dwellings that are exempt and in Line 2 compared with last year’s figure.

An explanation will be required where the total number of exemptions has changed by more than 100 and by more than 10% compared with the previous year’s figures.

Test 4: Number of demolished dwellings and dwellings outside area of authority on 2 October 2023

We will require an explanation if the change in the total number of demolished dwellings and dwellings outside the area of the authority, reported in Line 3, exceeds 20 compared to last year’s figure.

Test 5: Number of chargeable dwellings subject to a disability reduction on 2 October 2023

We will require an explanation if the total number of dwellings subject to a disabled reduction, reported in Line 5, has changed by more than 20 dwellings and by more than 5% on the previous year’s figures.

Test 6: Number of dwellings in line 7 entitled to a single adult household 25% discount on 2 October 2023

We will require an explanation if the total number of single adult discounts of 25%, reported in Line 8, has changed by more than 750 dwellings and by more than 2% on the previous year’s figures.

Test 7: Number of dwellings in line 7 entitled to a 25% discount on 2 October 2023 due to all but one resident being disregarded for council tax purposes

We will require an explanation if the total number of 25% discounts due to all but one resident being disregarded for council tax purposes, reported in Line 9, has changed by both more than 100 dwellings and by more than 10% on the previous year’s figures.

Test 8: Number of dwellings in line 7 entitled to a 50% discount on 2 October 2023 due to all residents being disregarded for council tax purposes.

We will require an explanation if the total number of 50% discounts due to all residents being disregarded for council tax purposes, reported in Line 10, has changed by more than 20 dwellings and by more than 5% on the previous year’s figures.

Test 9: Number of dwellings classed as second homes on 2 October 2023

We will require an explanation if the total number of second homes, reported in Line 11, has changed by both more than 100 dwellings and by more than 10% on the previous year’s figures.

Test 10: Number of dwellings classed as empty and receiving a zero% discount on 2 October 2023

We will require an explanation if the total number of empty homes receiving zero% discount, reported in Line 12, has changed by both more than 100 dwellings and by more than 25% on the previous year’s figures.

Test 11: Number of dwellings classed as empty and receiving a discount on 2 October 2023

We will require an explanation if the total number of empty homes receiving a discount, reported in Line 13, has changed by both more than 100 dwellings and by more than 25% on the previous year’s figures.

Test 12: Number of dwellings classed as empty and being charged the Empty Homes Premium on 2 October 2023

We will require an explanation if the total number of empty homes being charged a premium, reported in Line 14, has changed by both more than 50 dwellings and by more than 20% on the previous year’s figures.

Test 13: The total number of dwellings classed as empty on 2 October 2023

We will require an explanation if the total number of empty homes, reported in Line 15, has changed by both more than 100 dwellings and by more than 20% on the previous year’s figures.

Test 14: The total number of dwellings empty for more than 6 months after excluding properties empty due to flooding and those that previously would have received a class A exemption on 2 October 2023 (long-term empty dwellings)

We will require an explanation if the total number of long-term empty dwellings, reported in Line 18, has changed by both more than 200 dwellings and by more than 20% on the previous year’s figures.

Test 15: The number of dwellings subject to class O exemption on 2 October 2023

We will require an explanation if the number of dwellings subject to Class O exemption, reported in Line 25, has changed by more than 20 dwellings on the previous year’s figures.

Test 16: The tax base after council tax support on 2 October 2023

We will require an explanation if the tax base after council tax support, calculated in Line 31, has changed by more than 1,000 dwellings and by more than 2% on compared with the taxbase after council tax support reported on the CTR1 form in March 2023.

Test 17: Reduction in tax base as a result of local council tax support on 2 October 2023

We will require an explanation if the reduction to the tax base, calculated in Line 28, has changed by more than 250 dwellings and by more than 5% on the previous year’s figures.

Test 18: Family Annexe discount reduction on 2 October 2023

We will require an explanation if the reduction to the tax base as a result of the Family Annexe discount, as reported in Line 21, has changed by more than 5 dwellings on the previous year’s figures.

Supplementary form checks

Test 19: The number of dwellings subject to class F exemption (dwellings left empty by deceased persons) on 2 October 2023

We will require an explanation if the number of dwellings subject to Class F exemption has changed by more than 75 dwellings and by more than 10% on the previous year’s figures.

Test 20: The number of dwellings subject to class M and N exemptions (student exemptions) on 2 October 2023

We will require an explanation if the number of dwellings subject to Class M and N exemptions has changed by more than 100 dwellings and by more than 10% on the previous year’s figures.

Test 21: The number of dwellings subject to class U exemptions (dwellings occupied by a person, or persons, who is or are severely mentally impaired) on 2 October 2023

We will require an explanation if the number of dwellings subject to Class U exemption has changed by more than 25 dwellings and by more than 5% on the previous year’s figures.

Consistency checks

Test 22: Reduction in tax base due to Family Annexe discount on 2 October 2023

Check to ensure the reduction in tax base due to Family Annexe discount is at most 50% of the number of properties subject to the discount.

Test 23: Total number of exemptions

Check to ensure the total number of exemptions stated in CTB Form Line 2 matches that calculated in CTB Supplementary form Row 79.

Test 24: Total Class M and N exemptions

Check to ensure the total number of Class M & N exemptions stated in CTB Supplementary Part 1 matches that calculated in CTB Supplementary Part 3.

Test 25: The number of exempt dwellings as a percentage of the total stock.

An explanation will be required where the total number of exemptions in 2023 is greater than 4% of the total stock in 2023. This validation is based on Line 2 divided by Line 1 using this year’s CTB form. This validation is not compared with the previous year.