HEIC files and why forms reject them
Quick answerHEIC is Apple's photo format. Most websites only accept JPG. Convert with HEIC to JPG.
Modern iPhones save photos as HEIC because it stores good quality in about half the space of JPG. The trade-off is compatibility — most upload forms, Windows PCs and Android phones do not accept it.
The fix
Open HEIC to JPG, upload the photo, download the JPG. It works in Safari on the iPhone itself, so you do not need a computer.
Stopping it happening again
On your iPhone: Settings → Camera → Formats → Most Compatible. New photos save as JPG. Existing HEIC photos stay as they are until converted.
After converting
JPG files are larger than the HEIC original. If the form also has a size limit, run the JPG through Image Compress.
