Every plan allows a certain number of people in your workspace. You see how many places are taken under Members & Roles → Team members at the top of the card, next to Invite member — for example 3 of 3 seats taken.
On a paid plan you can book extra users at any time — at the monthly price per user the Store shows. Once you have, hover over the seat count on the member page to see the split, for example 3 included + 3 extra.
To a smaller plan: if the new plan has fewer places than you have members, UNENO suspends the extra ones automatically — the most recently added first, open invitations included. They then show the status Limited by plan. Nothing is deleted: roles and data are kept.
To a larger plan: UNENO gives members limited by plan their access back automatically — the longest-standing first, as many as there are new places. As the owner you also find Upgrade to restore in their ⋮ menu.
Fewer extra users: the reduction applies from the next billing date — until then every paid place stays usable. On the billing date the same happens as with a smaller plan.
More extra users: as with a larger plan, members limited by plan come back automatically, as many as there are new places.