Iwan Best way to check is to export a bank statement as PDF. Tap on the account on your Home tab, then open the More menu at the bottom and choose Export statement. Then create a PDF statement and on the the top left it will have the full information about the account holder with the first line being the name. In the case of a real Joint account, it will be names of multiple people, and in the case of a regular account shared through the Connect feature, it will just be the name of the main account holder.
In practice though, it doesn't matter so much because bunq will just accept the incoming payment anyway. I use Joint accounts at bunq but normally only tell people my own name and not the full line with all the account holders, never failed, so do as you please ;)
