Uploading is a challenging interaction for many users, particularly on desktop devices. It's somewhat easier on mobile devices, but still presents challenges. Users lower on the digital literacy scale will struggle and may not be able to use a service if they need to upload as part of it.
The most basic upload mechanism is the file picker. This can be difficult to use on desktop devices, but works well on mobile devices. You should support using a file picker as a minimum before adding alternatives.
Drag and drop
Proficient computer users may prefer to drag and drop from their file system onto the browser.
Always use another upload method alongside drag and drop.
Drag and drop only works in modern browsers
Users with dexterity problems such as tremor may have difficulty dragging a file.
You may want to support drag and drop to support users who attempt to drag a file, and would otherwise lose their progress in the service.
Is there any guidance / research around the most appropriate labels to use when asking for telephone numbers? Very conscious that the labels - Mobile / Home / Work will not be relevant for everyone ... we are also looking to test with Main phone + other phone
alex jaques We recommend you ask "How do you want to be contacted?" with checkboxes for home phone / mobile / text message, etc. See gif below. An advantage of this is a user who can't speak on the phone because is given an alternate contact method. For your service, how will deaf people use it?
This doesn't really help for contacting primary vs secondary numbers though. Lets see what others think. I wonder how relevant secondary phones are these days - my reckon is many will just give mobile.