You can invite other members of your company to join you in the same Travel Tree account. You go into settings, members, click – invite member. The invitation link is now copied. You can send it in any convenient way: via email, WhatsApp etc. Your colleagues click the link and go to the registration page. After registering, they are visible in the “Members”-section.
It is important, that your colleagues register through the invitation link. Only in this case they will be in the same account as you and you will be able to collaborate and see each others itineraries, notes etc.