The size of the photo should be at least 35 x 45 mm to leave margin for potential cropping and zooming. The most common size after cropping is 25 x 30 mm.
The image resolution should be a minimum of 160dpi to maintain high quality if zooming is required.
The resolution of the image should not exceed 300dpi.
Use a pale or neutral background without any shadow, use adequate lighting with no shadows or reflections.
The photo must be taken in full-face view.
Additional recommendations
To get even higher-quality cards, also consider using these rules for your photos:
Use a recent photo (within 6 months)
Full-face view, directly at the camera, showing edges of your face clearly and no tilting
Focus at head and upper shoulders so the head occupies 70-80% of the photograph
Both eyes open, visible pupils, no glare or shadows
No sunglasses or dark glasses
No head coverings, except for religious reasons, provided that the entire face is visible
No other individuals or animals in the photo
Accepted formats: .jpg or .png, no scanned or copied photos
Max file-size: 5mb