Form

CTR1/CTR2: Council Tax requirement return - data upload guidance

Updated 13 February 2026

Applies to England

Introduction

 Application of the guidance

This guidance is applicable for:

• Billing Authorities completing the CTR1 form and parish submissions
• Precepting authorities completing the CTR2 form

If you are responsible for the CTR3 (GLA) or CTR4 (Greater Manchester CA, South Yorkshire MCA, West Yorkshire CA or  York and North Yorkshire CA) form, then data needs to be directly entered into the DELTA system.

 Completing the forms in Excel or DELTA

We have provided equivalent CTR1 and CTR2 forms in Excel to authorities, so authorities can complete the form in Excel and upload the workbook to DELTA if they wish. We would recommend that the upload facility is used where billing authorities have multiple parishes and local precepting authorities. Calculations and validation checks based on these figures will be performed in the template so that they can be checked before data is uploaded into DELTA. If there are any outstanding validation checks, these forms will be saved rather than submitted.

Manual entry directly into DELTA is still available, and manual entry after the data has been uploaded can take place (for example, to change the data uploaded). However, any upload following manual entry will overwrite these changes.

Please read and follow the guidance carefully.

 Preparing your workbook for upload

 CTR1 form

For the CTR1 form, the workbook must be saved as an .xlsx file in order to upload the data to DELTA. The same workbook can be used to upload the data for the CTR1 submission and for the CTR1 Parish data submission.

For 2026-27, to ensure that the data uploads successfully, the first tab of the workbook must correspond to the data you are uploading. This means:

• If you are uploading the CTR1 data, the Upload_Data_CTR1_Billing tab must be the first tab in the workbook. 
• If you are uploading the Parish data, the Upload_Data_CTR1_Local tab must be the first tab in the workbook.

You can reorder the tabs by clicking and dragging them. Please do not delete or amend either the Upload_Data_CTR1_Billing tab or the Upload_Data_CTR1_Local tab. 

 CTR2 form

For the CTR2 form, the workbook will also need to be saved as an .xlsx file for a successful data upload.

 Dealing with issues

It is important to note that when uploading data to DELTA, some authorities may experience issues at both the upload and validation stages of the process. When experiencing an error here, the DELTA team recommends that authorities retry the file upload. If there are issues at the validation stage i.e., the system suggesting that rows are invalid, then we recommended continuing to the import stage of the upload. Once authorities have uploaded their workbook, validated the data, and started the import, the data will be processed in the DELTA system. It is worth noting that once the Import has started, this will continue in the background even if you get logged out or navigate away from the page.

This guide is for bulk upload via the CTR Excel Workbook and not for XML / API uploads. If you want to enter data directly into DELTA, see submit data.

 Instructions

1. Find and complete the CTR Excel Workbook, and save as an .xlsx file, with the correct tab as the first tab in the workbook (as detailed above).

2. Sign in to Delta. Once you have signed in,  you will be taken to the Welcome Page.

3. Under ‘Open collections’, find the CTR collection and click ‘View collection’. You will then see a page for the collection.

4. At the bottom of the page, you will see a section for returns. Select ‘Bulk upload’. Next to ‘Bulk upload’, there will be a button to ‘Download bulk upload template’ - please do not use this template to upload your data as it will not work. Please use the CTR Excel workbook provided.

5. Select ‘Upload data’ in the dropdown menu. Choose ‘Select file’ and select the CTR Excel Workbook from your computer or drag and drop the file in the box.

6. Once you have selected the file, a green box at the bottom will say ‘Upload complete’. The file is now uploaded, but it still needs to be checked for errors and imported into the system. Select ‘Next’. This will take you to the validation page which will tell you if your data is valid or invalid. In some instances, this first upload can fail. We recommend retrying in the first instance.

7. This will then start the DELTA validation. Be aware this may take a minute or two depending on how much data is being loaded. You will need to wait until a green text box appears.

• If it is valid, it means DELTA cannot find errors on the data. It will be imported, and its status will be ‘Submitted’. You can still view or edit the form in the data store. Once your data has been successfully submitted, you will receive a confirmation email. You can follow the ‘view completed results’ link to go to the data store.

• If it says ‘x out of x document is invalid’ this means there are data problems, or further review or explanatory comments are required before it can be submitted. Please continue with the upload. It will show as ‘Saved’ rather than submitted. You will then need to edit the form on DELTA later to resolve the issues and submit. In some cases, the system can suggest that all documents are invalid on upload. We recommend that authorities continue with the import stage where this is the case.

8. Click ‘Next’ to proceed to import the record.

• If there are existing records previously uploaded or submitted for this collection for your organisation, you will be asked if you want to ‘Keep’ or ‘Delete’ before you ‘Start Import’. Please select the ‘Delete’ option, as there can only be one record for the CTR1/CTR2 collection.
• The imported data will overwrite any existing data. This includes replacing previously reported values with blanks if these cells have been left blank in the re-uploaded template and overwriting changes made directly into DELTA.
• If presented with an option to ‘Import’ or ‘Skip’, select the ‘Import’ option, not the ‘Skip’ option.

9. Click on ‘Start import’. Once the Import has started, this will continue in the background even if you get logged out or navigate away from the page.

10. A message in a green box will appear to say the import of the document is complete. Clicking on ‘Close’ will take you to the data store.

11. Please check your data in the data store. You can view or edit individual records by selecting ‘More’ next to each record. Use the Status filter to show only ‘Saved’ records (these are records that have not yet been submitted). If you edit a saved record, you will be able to view the error and then submit it. 

To view all records, you may use the ‘Download CSV’ option at the top of the data store page. Please ensure that all records are submitted.

Note - for CTR1/Parishes: If the first tab of the uploaded workbook does not correspond with the form you are uploading data for, the data store will display either: 

• 1 blank record for Parishes, or 

• Multiple blank records for CTR1 

If this occurs, please amend your workbook so that the correct tab appears first. Then repeat the bulk upload process, ensuring that the ‘Delete’ option is selected on the Import page to delete the records previously uploaded.

12. To ensure that authorities are satisfied with the data that has been uploaded to the DELTA system, for the CTR1 form you will be required to edit the form to answer a checkbox confirming whether you have used the bulk upload facility.

13. Once you have successfully submitted your data, you will get an email confirmation.

Submitting the form/dealing with validations

• Each parish will be saved/submitted on DELTA as a separate record. If you need to amend data for specific parishes or provide additional validation comments you can do so via their individual records rather than completing another bulk upload.

• To review, manually edit, and submit the data you must go into the form in DELTA. To do this click on ‘More’ and choose ‘Edit form’.

• Please address any validation warnings and errors e.g., by adding in explanations, and then completing your return by pressing on the green ‘Submit’ button at the foot of the form. Please note that some validation warnings may not show up until you attempt to submit the form.

What to do if you need to bulk upload again

• If you need to carry out an additional bulk upload, DELTA has the capability to re-upload data. Follow the steps above.

Be Aware: A bulk upload will replace all data and comments, and therefore you will need to fill in explanations again to satisfy error flags. Therefore, you may prefer to make changes directly in DELTA.

Queries

• If you have any queries regarding bulk upload, please email us at ctr.statistics@communities.gov.uk.