What happens to my add-on seats when I change plans?

Add-on seats come with you — re-priced immediately on upgrades and at your next renewal on downgrades.

They come with you. On an upgrade your add-on seats move to the new plan’s per-seat rate right away (prorated onto your next invoice, like the plan change itself); on a downgrade they switch over at your next renewal. If you move to a plan that doesn’t sell add-on seats, the add-ons are removed at that point and you stop being billed for them — the people over the new limit keep their access, you just can’t invite past it until you’re back under.