What the specification means in practice
Mexico uses a 45 × 35 mm photo on a white background, front-on, with the whole head in frame. The distinctive constraint is time: the photo must have been taken no more than 30 days before the application. Every other specification on this site allows six months, and the UK’s one-month rule for printed photos is the only thing that comes close.
Thirty days, not six months
Plan the photo around the appointment rather than the other way round. A photo made when you started gathering documents may well be outside the window by the time you are seen, and there is no way to tell by looking at it — which means the check happens at the counter, when it is too late to do anything but leave and come back.
No smiling, no glasses
The instruction is explicit on both: sin sonreír and sin lentes. A neutral expression with the mouth closed, and glasses removed. This is stricter on expression than the several specifications that tolerate a slight closed-mouth smile, and it puts Mexico alongside the United States and Australia on glasses.
The head must be complete in frame — cabeza completa. Photos where the head is cut off at the top, where the face is too close to the camera, where the subject is too far away, or where the head is turned to the side or shown in profile are all named as unacceptable.
A white background that is actually white
The background must be white, and a grey or stained background is specifically listed as a rejection. A white wall that photographs grey under warm indoor lighting is the usual culprit — the wall is white, the photograph is not. Shoot in daylight, or expose for the background rather than the face.
Requirements vary by office
This is the specification on the site with the least consistency between sources. Different SRE delegations and consulates publish photo sizes that do not exactly agree — some state a minimum and maximum size range rather than a single figure, and the number of photos requested varies too.
The measurement recorded here comes from an official SRE consular publication, but treat it as the starting point and confirm against the specific office handling your application. Where a Mexican office publishes its own requirement, that requirement is the one that applies to you.
What is not published
The SRE does not publish a chin-to-crown head height for the Mexican passport photo, so no head-height ratio is recorded in our dataset. Rather than invent one, frame the photo so the whole head is comfortably inside the frame with a small margin above the hair, and follow the published examples of correct and incorrect photos.