This is the commonly used size: we found no requirement published by the institution. Confirm it before your application.
Tips to get it right the first time
GOV.UK asks for a recent digital photo showing your head and shoulders.
Your local council runs the application: check its own photo rules before uploading.
Face the camera with a neutral expression and nobody else in the photo.
How to do it with Requisito Listo
Open the «Blue Badge photo» template in the app.
Take the photo with the on-screen guide (or pick one from your gallery).
The app centers your face, makes the background white and gets the exact size and file weight.
Check the checklist, then upload or save it.
At the end you'll see a checklist: size, file weight, background and format. If something doesn't comply, it tells you what to fix before the portal rejects it.