Formatting a dataset

Finding out what format your users need your data in is the best approach to providing a data download. Depending on the size of your data, datasets can be provided as XLS or CSV. If you are looking to use a compressed version of a large amount of data, a CSV file is best for this – but bear in mind that CSV files are designed to be read by machines and do not allow any formatting.

Large datasets can be provided as a zip file so that they can easily be uploaded to our content management system.

Datasets should have a unique, lowercase file name, using dashes instead of spaces or underscores between words. The file name should make it clear what is included in the data download so that it makes sense to users out of context.


  • Use sensible tab names and ensure the file opens on the first tab to avoid confusion.
  • Include contact details and the date of the next update on the first tab.
  • Separate tables out onto individual worksheets for easy navigation.
  • Remove blank tabs and extra spaces from the start or end of tab names.

Table structure

  • Use a simple table structure with clear headings and subheadings.
  • Use clear and consistent titles across all tables for straightforward data usability.
  • Do not split or merge cells as this affects accessibility.
  • Do not hide or use blank rows or columns, instead adjust the column width and row height to create space. 
  • Avoid including images and charts.

Do not use colour in a table to convey meaning that is not shown in another way, as this can make the text hard to read and distinguish from the background. This can cause accessibility issues for users with low vision or who have difficulty with colour contrast.

Codes and symbols

  • Use nationally recognised classifications, such as geography codes, and keep users updated with any changes to these where possible.
  • If you are using symbols for communicating uncertainty, include a guide to explain to users what each of these mean.  
  • Add codes and symbols in a separate column to the data.
  • Avoid using indentation to show geographic hierarchy. 

The Government Statistical Service (GSS) provides further detailed guidance on releasing statistics in spreadsheets. 

Read more on best practice on dataset accessibility.

We are constantly improving based on research and best practice. Any significant changes to our guidance are available on the Updates page.