Teams Guest Names - you only have one chance!
When you add an external Guest to your Team, you only get one shot at setting their display name (unless you are a Microsoft 365 Admin), so make sure you do it right the first time.
Once you’ve entered their email address and hit ‘Add (address) as a guest’, your one-shot is the tiny pencil highlighted in the second graphic. Using this, you can type their real name in, rather than the one generated from their email address. You don’t get any other opportunity…
We recommend that you put in the person’s full name, even if you don’t think you need the surname at the moment.
TOP TIP: Make sure you spell their name correctly – they’ll be very grumpy if they are permanently spelt wrong in your systems!
(But don’t worry – your Admin can correct it for you… though it can take a while for changes to propagate).
