ONS Statistics

ONS Statistics

The Office for National Statistics (ONS) is the UK's largest independent producer of official statistics. This API provides programmatic access to CMD (Customise My Data) datasets.

Data Model

• Dataset — A named collection of observations (e.g. cpih01 = CPIH inflation). Has editions and versions.
• Edition — A release track within a dataset (typically "time-series").
• Version — A numbered snapshot of an edition. The latest version has the most recent data.
• Dimensions — The axes of a dataset (e.g. time, geography, aggregate). Each version has its own set of dimension options.
• Observations — Individual data points filtered by dimension values.

Common Datasets

• cpih01 — CPIH (Consumer Prices Index including owner occupiers' housing costs)
• mid-year-pop-est — Mid-year population estimates
• wellbeing-quarterly — Personal well-being quarterly estimates
• regional-gdp-by-year — Regional GDP estimates

Workflow

1. Search or list datasets to find the one you need.
2. Get dataset details and its editions.
3. List versions of an edition, pick the latest.
4. List dimensions and their options for that version.
5. Query observations with specific dimension filters.

Gotchas

• Observations require all dimensions: Every dimension of the dataset must be specified as a query parameter.
• Dimension option codes: Use the dimension options endpoint to discover valid codes before querying observations.
• Search is broad: The search endpoint covers all ONS content (articles, bulletins, datasets), use content_type filter to narrow.
• No auth: Fully public API with generous rate limits.