United Kingdom Passport Photo Size

In short A United Kingdom passport photo is 35 × 45 mm with the head measuring 29 to 34 mm from crown to chin, on a light grey or cream background. That head range works out at 64 to 76 per cent of the image height, which is outside the 70 to 80 per cent ICAO Doc 9303 asks for, and deliberately so. That is precisely why a photo cut to another country's requirements is likely to be refused here even when the paper size matches. The British head range of 29–34 mm is measurably shorter than the Schengen 32–36 mm on an identical 35 × 45 mm photo, so a picture cropped to EU requirements is usually rejected in the UK for the head being too large. The two look interchangeable and are not. In pixels, the print needs 414 × 532 at 300 dpi, which is the normal minimum for printing, and 827 × 1063 at 600 dpi, which is what many online applications ask for. Note that dpi is not a property of a file at all — it is the pixel count divided by the print size, so quoting megapixels answers a different question. What none of this settles is whether a particular photograph will be accepted: size, head height and background are the measurable part, while expression, lighting, shadow on the background, glare on spectacles and hair across the face are judged by a person, and any of them can fail a photo that is correct to the millimetre.