For accounts with a verified email or phone number, it is possible to log into the Snapfix account using a once-off code. The code can be send to a phone using SMS or to an email inbox.
To request a code, on the login screen, put in your phone number or email. Then on the next page you'll have the option to request the once-off code.
NOTE: If your phone number of email address is not verified, you can not request a login code.