Inviting others to work with you on a group is simple.
Head to the Settings area using the left-hand navigation
Choose Invite a Team Mate, and then enter the email address they use to log in to Xero with
They will receive an email inviting them to log in to Mayday, but feel free to send them the login link (https://recharger.getmayday.com) where they will be able to get in.