Check the file

• Size — must be 5MB or less.
• Format — PDF, JPG, JPEG, PNG, DOC or DOCX only.
• Name — avoid unusual symbols; letters, numbers, hyphens and underscores are safest.

Reducing size

Photograph the document instead of scanning it, or lower your camera's resolution setting. A phone photo at medium quality is almost always under 5MB and still perfectly readable.

Still failing

Try a different browser or a private window. If the file is genuinely valid and it still will not upload, raise a support ticket describing the file type and size.