Official price cap data

Ofgem’s price cap in force, the next one once Ofgem has announced it, and the observation calendar Ofgem publishes, as a read-only JSON feed. No API key is needed. Browser requests are supported.

GET /api/energy-price-cap

The feed and the embed carry Ofgem’s figures only. Our forecast of the next cap is published on our price cap page and isn’t part of either.

Credit

The figures are Ofgem’s, published under the Open Government Licence v3.0. If you show them from this feed, put Source: Switch4Good beside them, linked to our price cap page, and credit Ofgem.

<a href="https://www.switch4good.co.uk/energy-price-cap">Source: Switch4Good</a>

The embed

Paste this into your page to show the current cap and where the observation window has got to. The credit is part of the frame. The frame sets no cookies and runs no analytics; we count loads by the referring site and day only.

<iframe src="https://www.switch4good.co.uk/embed/energy-price-cap" title="Energy price cap, from Switch4Good" width="100%" height="680" style="border:0;max-width:720px" loading="lazy"></iframe>

It works from 300 pixels wide. Make the frame taller if your column is narrow.

What the feed returns

  • schema_version: 2.0 from 2 October 2026.
  • current: the verified cap in force, its effective dates, typical consumption and Ofgem source.
  • next_confirmed: the next cap once Ofgem has published it, with its dates and source; otherwise null.
  • observation_window: the next unclosed window in Ofgem’s published calendar. This can be for a later quarter than the next cap. Calendar progress doesn’t measure how much of the final cap is fixed.
  • notes: changes to the feed’s shape, dated.
  • attribution: the credit and link.

All monetary fields ending in _gbp are pounds sterling (£), not pence. The annual figure is for typical consumption, not a ceiling on anyone’s bill.

Dates and caching

The feed selects the current period using UK dates. Responses are cached for up to ten minutes and never past UK midnight. Fetch at most once every 15 minutes; more than 60 requests a minute from one address are refused. Recheck at UK midnight on effective dates. When a section is being_updated, hide any number you cached for it.

Only checked, published cap records become current. New Ofgem workbooks are validated before release, so a section can be unavailable while that happens.

What changed

Until 2 October 2026 the feed and the embed also carried our provisional forecast. They no longer do. The forecast stays on our own pages.

Back to the price cap